The complex [closo-3,3-(PPh<sub>3</sub>)<sub>2</sub>-3-H-3,1,2-RhC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]has a rich derivative chemistrythat is currently ...The complex [closo-3,3-(PPh<sub>3</sub>)<sub>2</sub>-3-H-3,1,2-RhC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]has a rich derivative chemistrythat is currently under active investigation.The resultant compound shows an increasing stabilitythat is often associated with metallocarboranes.This paper deals with the novel and the produc-tion area of carborane complexes of transition metals.The paper indicates that some reactions can easily proceed and the resulting compound hassome new properties and uses.K[18-crown-6][closo-3-Ph<sub>3</sub>P-3-CH<sub>2</sub>Ph-3-Br-3,1,2-RhC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]can be synthesized by the reaction of K[18-crown-6][(Ph<sub>3</sub>P)<sub>2</sub>RhC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]withbromo-toluene under the condition of dry benzene.IR and <sup>1</sup>H,<sup>11</sup>B,<sup>31</sup>p nuclear magnetic reso-nance and elemental analysis comfirm the structure for this species with one carborane groupbonded to the central metal.展开更多
Halfsandwich iron dicarbonyl complex [η 5-C5H3(t-Bu)2]Fe(CO)2Cl(1) reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10(2) to give a binuclear iron carborane complex [η 5-C5H3(t-Bu)2]2Fe2(CO)3&...Halfsandwich iron dicarbonyl complex [η 5-C5H3(t-Bu)2]Fe(CO)2Cl(1) reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10(2) to give a binuclear iron carborane complex [η 5-C5H3(t-Bu)2]2Fe2(CO)3·Se2C2B 10H 10(3). The X-ray diffraction analysis of complex 3 reveals that one of the iron atoms is chiral.展开更多
A new compound [CpCo(Se2C2BIoH9)CH2C(O)C4H30] has been synthesized and characterized by elemental analysis, IR spectroscopy, NMR, MS and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic...A new compound [CpCo(Se2C2BIoH9)CH2C(O)C4H30] has been synthesized and characterized by elemental analysis, IR spectroscopy, NMR, MS and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P21/c with a = 10.9481(10), b = 24.6600(12), c = 25.7430(14) A, β = 100.863(3)°, C42H57B30Co306Se6"CH2C12"0.25H20, Mr = 1722.16, V = 6825.6(8) A3, Dc= 1.676 g/cm3, Z = 1 and F(000) = 3346. The molecular structure shows a 1:1 ratio product of the two reactants of 16e half-sandwich complex CpCo(Se2C2B10H10) and alkyne 1-(2-furyl)-2-propyn-l-one. The hydrogen atom in the B(3) position of CpCo(Se2C2B10HIo) has been activated and migrated to the terminal carbon of 1-(2-furyl)- 2-propyn-l-one to form the B-CH2 unit. The title compound molecules are linked and extended further into a one-dimensional chain through atypical hydrogen bonds.展开更多
This work describes a general method for the synthesis of a series of sulfenylated and selenylated carboranes at room temperature using readily available iodocarboranes as starting materials via boron-centered carbora...This work describes a general method for the synthesis of a series of sulfenylated and selenylated carboranes at room temperature using readily available iodocarboranes as starting materials via boron-centered carboranyl radicals.Such hypervalent boron radicals are generated by a visible-light-promoted Pd(O)/Pd(I)pathway.They are useful intermediates and can be trapped by disulfides and phenylselenyl chloride for the convenient construction of B-S/Sebonds.展开更多
Using the experimentally known aromatic icosahedral superatoms I_(h)B_(12)H_(12)2−and D_(5d)1,12-C_(2)B_(10)H_(12)as building blocks and based on extensive density functional theory calculations,we predict herein a se...Using the experimentally known aromatic icosahedral superatoms I_(h)B_(12)H_(12)2−and D_(5d)1,12-C_(2)B_(10)H_(12)as building blocks and based on extensive density functional theory calculations,we predict herein a series of core–shell superpolyhedral boranes and carboranes in a bottom-up approach,including the high-symmetry Th B_(12)@B_(152)H_(72)2−(2),C2h C_(2)B_(10)@B_(152)H_(72)(3),D_(3d)B_(12)@B_(144)H_(66)(4),I_(h)B_(12)@C_(24)B_(12)0H_(72)2−(6),and D_(5d)C_(2)B_(10)@C_(24)B_(12)0H_(72)(7).More interestingly,the superatom-assembled linear D2h B_(36)H_(32)^(2−)(8),close-packed planar D_(3d)B_(84)H_(60)^(2−)(10),and nearly close-packed core−shell D_(3d)B_(12)@B144H_(6)6(4)can be extended periodically to form the one-dimensional(1D)α-rhombohedral borane nanowire B_(12)H_(10)(Pmmm)(9),two-dimensional(2D)α-rhombohedral monolayer borophane B_(12)H_(6)(P m1)(11),and the experimentally known three-dimensional(3D)α-rhombohedral boron(R m)(12)which can be viewed as an assembly of the monolayer B_(12)H_(6)(11)staggered in vertical direction,setting up a bottom-up strategy to form low-dimensional boron-based nanomaterials from their borane“seeds”via partial or complete dehydrogenations.Detailed bonding analyses indicate that the high stability of these nanostructures originates from the spherical aromaticity of their icosahedral B_(12)or C_(2)B_(10)structural units which possess the universal skeleton electronic configuration of 1S21P61D101F8 following the Wade’s n+1 rule.The infrared(IR)and Raman spectra of the most-concerned neutral B_(12)@B144H_(6)6(4)and C_(2)B_(10)@C_(24)B_(12)0H_(72)(7)are computationally simulated to facilitate their experimental characterizations.展开更多
Though transition metal-catalyzed cage BH methylation has been well documented, catalytic alkylation of cage BH bonds remained elusive because transition metal alkyl complexes are prone to undergo β-H elimination. We...Though transition metal-catalyzed cage BH methylation has been well documented, catalytic alkylation of cage BH bonds remained elusive because transition metal alkyl complexes are prone to undergo β-H elimination. We report herein a highly efficient 8-aminoquinoline-assisted nickel-catalyzed regioselective cage B(3,4,5,6)-H tetra-alkylation of o-carboranes employing unactivated alkyl bromides as alkylating agents in the absence of any oxidants, leading to the preparation of a class of tetra-alkylated o-carboranes with a broad substrate scope in good to very high yields. This method opens new avenues for oxidant-free, direct, efficient, sustainable, and regioselective multiple B–H alkylation of carboranes via base metal catalysis.展开更多
Herein,we describe the synthesis of a carborane-supported octanuclear palladacycle complex,Pd_(8)(o-C_(2)B_(10)H_(10)CS_(2)CH_(3))_(4)Cl_(4)(CH_(3)CN)_(4)(complex 1),with B(3)-H activations on o-carborane ligand.The s...Herein,we describe the synthesis of a carborane-supported octanuclear palladacycle complex,Pd_(8)(o-C_(2)B_(10)H_(10)CS_(2)CH_(3))_(4)Cl_(4)(CH_(3)CN)_(4)(complex 1),with B(3)-H activations on o-carborane ligand.The substitution reaction of 1 has been explored,and three of its substituted complexes Pd_(8)(o-C_(2)B_(10)H_(10)CS_(2)CH_(3))_(4)Cl_(4)(L)4(L=^(t)BuNC,2;L=C_(5)H_(5)N,3;L=C_(4)H_(8)S,4)have been synthesized.The m-and p-carborane disubstituted ligands m-and p-C_(2)B_(10)H_(10)(CS_(2)CH_(3))_(2)(ligands 5 and 6)as well as their B—H activated carborane complexes[m-C_(2)B_(10)H_(9)(CS_(2)CH_(3))_(2)PdCl](7)and[p-C_(2)B_(10)H_(8)(CS_(2)CH_(3))_(2)][PdCl(^(t)BuNC)]_(2)(8)have also been synthesized by the similar method.All of these complexes have been characterized,including X-ray single crystal diffraction,NMR spectroscopy,IR spectroscopy and elemental analysis methods.展开更多
The reasons for facile double desilylation of 13-vertex carborane 1,2-Me_(2)Si(CH_(2))_(2)-1,2-C_(2)B_(11)H_(11)(2)are discussed in this article.New 13-and 14-vertex ruthenacarboranes bearing the same-CH_(2)SiMe_(2)CH...The reasons for facile double desilylation of 13-vertex carborane 1,2-Me_(2)Si(CH_(2))_(2)-1,2-C_(2)B_(11)H_(11)(2)are discussed in this article.New 13-and 14-vertex ruthenacarboranes bearing the same-CH_(2)SiMe_(2)CH_(2)-linkage have been prepared and structurally characterized for comparison.Structural analyses of 13-and 14-vertex heteroboranes as well as control experiments suggest that the facile double desilylation of 2 on silica gel can be attributed to the joint actions of several factors involving the high ring-strain of exo five-membered C_(4)Si ring,Lewis acidity of Si atom and Brønsted acidity of silica surface.展开更多
The steric and electronic properties of A/-heterocyclic carbenes(NHCs)can be modified by the exocyclic substituents at the nitrogen atoms,by 1-3 atoms'replacements of the five-membered imidazolium skeleton and by ...The steric and electronic properties of A/-heterocyclic carbenes(NHCs)can be modified by the exocyclic substituents at the nitrogen atoms,by 1-3 atoms'replacements of the five-membered imidazolium skeleton and by the changes of the backbones.Herein,we report the usage of nido-C_(2)B_(3) carbora ne anions as the backb ones of NHCs.Stirring the mixture of sec on dary amino o-carbora nes(lb-le),triethyl orthoformate and HBF4-Et2O results in the unexpected cage-opening of o-carboranes to afford the n/do-C_(2)B_(9) carbora ne anions supported A/-heterocyclic carbene precursors(4b-4e).Deprotonation of 4b with sodium hexamethyldisilazide at-78℃ affords the/V-heterocyclic carbene ligand,which was used to form an Au(I)NHC complex(5).DFT calculations revealed a high-lying lone pair orbitals of the carbene ligands,predicting their strong o-donating abilities.展开更多
o-Carboryne (1,2-dehydro-o-carborane) is a very useful synthon for the synthesis of a variety of carborane-functionalized molecules. Diels-Alder reaction of o-carboryne with furans gave a series of carborane-fused o...o-Carboryne (1,2-dehydro-o-carborane) is a very useful synthon for the synthesis of a variety of carborane-functionalized molecules. Diels-Alder reaction of o-carboryne with furans gave a series of carborane-fused oxanorbornenes in moderate to high yields using 1-OTf-1,2-C_2B_10H_11 as carboryne precursor. The resultant cycloadducts can undergo hydrogenation, cyclic oxidation, bromination, [4+2]/[2+2] cycloaddition and nucleophilic ring opening reaction to afford a variety of highly functionalized carboranes that may find applications as useful basic units in medicine and materials science.展开更多
In this study, two fluorinated polyurethanes(FPU) containing carborane groups in the main chains were firstly designed and synthesized via the reaction of hexamethylene diisocyanate trimer(HDI trimer) with fluorin...In this study, two fluorinated polyurethanes(FPU) containing carborane groups in the main chains were firstly designed and synthesized via the reaction of hexamethylene diisocyanate trimer(HDI trimer) with fluorinated polyesters(CFPETs) having hydroxyl-terminated carborane groups at room temperature. The structures of carborane fluorinated polyesters(CFPETs) and polyurethanes(CFPUs) were characterized by gel permeation chromatography(GPC), Fourier transform infrared(FTIR) spectroscopy and nuclear magnetic resonance(NMR) measurements. The thermal stability, mechanical properties, Shore A hardness, solvent resistance and acid-alkali resistance of the carborane fluorinated polyurethane films were also studied. Thermogravimetric analysis(TGA) tests manifested that the introduction of carborane groups into the main chain of fluorinated polyurethane endowed the obtained fluorinated polyurethane with excellent thermal stability. The thermal decomposition temperature of carborane fluorinated polyurethane(CFPU) increased by 190 °C compared with that of the carborane-free fluorinated polyurethane(FPU). Even at 800 °C, CFPU showed the char yield of 66.5%, which was higher than that of FPU(34.3%). The carborane-containing fluorinated polyurethanes also showed excellent chemical resistance and prominent mechanical property even after the cured films being immersed into Jet aircraft oil or 37% HCl for 168 h or at high temperature(700 °C). It is found that the structural characteristics of carborane group and the compacted structure of CFPU effectively improve the thermal stability, mechanical property, solvent resistance and acid-alkali resistance of the carborane-free fluorinated polyurethane. These excellent properties make CFPU as the useful raw materials to prepare the high temperature resistant coatings or adhesives for automotive engines, engine or fuel tank of aircraft and other equipment working in high-temperature or high concentrations of acid-alkali environments.展开更多
Carborane bisphenol novolacs (3 and 4) were synthesized in the presence of acid catalyst from carborane bisphenols (5 and 6) and formaldehyde. Further epoxidization of carborane bisphenol novolacs with epichlorohy...Carborane bisphenol novolacs (3 and 4) were synthesized in the presence of acid catalyst from carborane bisphenols (5 and 6) and formaldehyde. Further epoxidization of carborane bisphenol novolacs with epichlorohydrin gave carborane bisphenol epoxy novolacs (1 and 2). The molecular weight and epoxy value of obtained resins were determined using the molecular weight of their precursors. The epoxy values of 1 and 2 were 0.48 and 0.52 respectively, higher than the maximum theoretical epoxy value (0.45) of difunctional carborane bisphenol epoxy resins. FTIR and NMR were utilized to characterize 1 and 2. The curing behaviors were also studied by DSC and the optimized curing conditions were obtained. TGA analysis indicated that carborane moiety could shield its adjacent organic structures against initial decomposition. On the other hand, B--H on carborane cage could react with oxygen to form a three-dimensional network linked by B--O--B and B--C bonds, which further blocked the movement of formed radicals and thus the degradation process was inhibited.展开更多
o-Carborane-containing poly(hydroxy ethers)(P1, P2 and P3) were synthesized via "advancement reaction" of o-carborane-containing bisphenol(4) and diglycidyl ether of bisphenols(DGEBA and 1). FTIR and 1^H^-,...o-Carborane-containing poly(hydroxy ethers)(P1, P2 and P3) were synthesized via "advancement reaction" of o-carborane-containing bisphenol(4) and diglycidyl ether of bisphenols(DGEBA and 1). FTIR and 1^H^-, 13^C^-, and 11^ B-NMR were utilized to characterize the obtained polymers. TGA test was conducted under nitrogen and air. It is found that the shielding effect of carborane moiety on its adjacent aromatic structures contributes to high initial decomposition temperatures, while oxygen in air has an adverse effect on the initial decomposition temperature. The oxygen can combine with polymer chain to form peroxide and hydroperoxide groups, which are more reactive during the degradation process. Besides, o-carborane-containing poly(hydroxy ethers) have high char yield at elevated temperatures. The boron atom combines with oxygen from the polymer structure or/and from air, thus to form a three-dimensional network linked with B―O―B and B―C bonds, and retain the polymer weight to a large extent.展开更多
We report herein a practical approach for regio-selective B—H/C—H bond activation at azo-substituted carboranes. The reaction proceeded through Iridium(III)-induced selective B—H/C—H bond activations based on an a...We report herein a practical approach for regio-selective B—H/C—H bond activation at azo-substituted carboranes. The reaction proceeded through Iridium(III)-induced selective B—H/C—H bond activations based on an azo directing group. Through this strategy, a series of mononuclear, trinuclear and tetranuclear cyclometalated iridium complexes containing Cp*Ir—B or Cp*Ir—C bonds were successfully isolated in a high yield. In this work, efficient routes are developed through one-pot reactions to prepare polynuclear organometallic complexes.展开更多
Carboranes are a class of polyhedral boron-carbon molecular clusters,they can serve as versatile ligands in stabilizing low-valent main group element compounds,due to their exceptionally thermal and chemical stabiliti...Carboranes are a class of polyhedral boron-carbon molecular clusters,they can serve as versatile ligands in stabilizing low-valent main group element compounds,due to their exceptionally thermal and chemical stabilities,easy modifications at the cage carbon vertices,as well as large spherical steric effects.These carborane-based ligands provide interesting opportunities for the synthesis of low-valent main group element compounds with novel structure and reactivity,which indeed enrich the chemistry of low-valent element main group compounds.This review summarizes the recent advances in the chemistry of lowvalent group 13 and group 14 element compounds supported by carborane-based ligands.Achievements and perspectives in this new and flourishing field are discussed in this review.展开更多
Metallocene complex Cp tt 2ZrCl 2 (Cp tt =η 5 1,3 t Bu 2 C 5 H 3 ) (1) has been prepared from the reaction of LiCp tt with ZrCl 4 in good yield. Reactio...Metallocene complex Cp tt 2ZrCl 2 (Cp tt =η 5 1,3 t Bu 2 C 5 H 3 ) (1) has been prepared from the reaction of LiCp tt with ZrCl 4 in good yield. Reactions of 1 with dilithium dichalcogenolate o carboranes afforded new type of half sandwich compounds with dichalcogenolate o carboranyl ligands, [Li(THF) 4 ][Cp tt Zr(E 2 C 2 B 10 H 10 ) 2 ] (E=S, 2a; E=Se, 2b) in which only one cyclopentadienyl ring ligand existed. Complexes 1 and 2a were structurally characterized by X ray analyses. In complex 2a, the Zr(IV) ion is η 5 bound to one 1,3 di tert cyclopentadienyl ring and σ bound to four μ 2 sulfur atoms of two dithio carboranes. The zirconium atom and four sulfur atoms form a distorted pyramid. The coordination sphere around the zirconium atom resembles in a piano stool structure with four legs of sulfur atoms and the fulcrum at the zirconium atom.展开更多
Ligand modifications have played a crucial role in developing new catalyst precursors. A novel class of “constrained-geometry”ligands bearing a carboanion functionality has been developed by linking o-carboranyl and...Ligand modifications have played a crucial role in developing new catalyst precursors. A novel class of “constrained-geometry”ligands bearing a carboanion functionality has been developed by linking o-carboranyl and n-ligand together. They offer group 4 metal complexes higher activity in olefin polymerization compared to those with appeoded heteroatom systems. The results show that the [{η^5:σ-Me2A(C5H4)(C2B10H10)}M] moiety remains intact in olefin polymerization and insertion reactions of various unsaturated molecules, and the electron-deficient yet sterically hindered icosahedral carborane does play an important role in the reactions. This article provides an overview of our recent work on this subject.展开更多
Persistent homology is a powerful and novel tool for quantifying the inherent topological features of structure. In this work, we used the persistent homology for the first time to study the closo-carboranes C2Bn-2Hn(...Persistent homology is a powerful and novel tool for quantifying the inherent topological features of structure. In this work, we used the persistent homology for the first time to study the closo-carboranes C2Bn-2Hn(n = 5~20) and their parent structures closo-boranes dianions BnHn2-(n = 5~20), where multiple elements are present. All these structures are first investigated with the standard Vitoris-Rips complex. We interpret all barcodes representation and associate them with structural details. By means of average bar length, a linear regression model was established to construct the relationship between persistent homology features and molecular stability, which was expressed by the relative energies. For closo-boranes dianions, we only use B atom set since B and H atoms are in pairs. The average lengths of β0, β1 and β2 bars are used as the features for linear regression, and excellent correlation coefficient(0.977) between the values predicted by persistent homology and those by quantum calculations was achieved. For closo-carboranes, C–B atom set(ignore the differences in the atoms), B atom set and C atom set were considered to get the persistent homology features(since there were only two C atoms in C2Bn-2Hn, only β0 bars were considered), and seven average bar lengths were calculated, respectively. Pearson coefficient of 0.937 was obtained. We found that the stability of carboranes showed a high linear correlation with the characteristics generated from topological bars in H0, H1 and H2. The results show that the topological information generated by persistent homology can be extended and applied to multi-element systems.展开更多
We designed the triad molecule,bis-o-carborane-substituted bis(thienylethynyl)benzene,as a filler for realizing thermochromic luminescent behaviors based on conventional polymer films,such as polystyrene.From the opti...We designed the triad molecule,bis-o-carborane-substituted bis(thienylethynyl)benzene,as a filler for realizing thermochromic luminescent behaviors based on conventional polymer films,such as polystyrene.From the optical measurements,it was found that the triad can show solid-state emission and dual-luminescent properties with variable intensity ratios depending on media.From the mechanistic studies including the experiments with the methyl-substituted model compound,it was revealed that dual emission should be originated from the locally excited and twisted intramolecular charge transfer states,and the latter emission band is significantly enhanced in the solid states.We prepared amorphous films containing variable concentrations of the triad with the spin-coating method and investigated optical properties.It was found that intensity ratios were drastically changed by altering the concentration of the triad.By increasing the proportion of the triad,aggregation occurred,and emission color was apparently varied through the changes in intensity ratios of the dual emission property.Based on the aggregationinduced luminochromic property of the triad,thermochromic luminescence was finally realized by heating the amorphous films.The rational design for obtaining thermochromic luminescent amorphous films is illustrated in this paper.展开更多
The syntheses of trislanes containing C-monosubstituted o-carborane are described.Hie intermediate compound,2-chloro-2-phenyl-hexamethyltrisilane,was prepared by elimination reaction between 2,2-diphenylhexamethyltris...The syntheses of trislanes containing C-monosubstituted o-carborane are described.Hie intermediate compound,2-chloro-2-phenyl-hexamethyltrisilane,was prepared by elimination reaction between 2,2-diphenylhexamethyltrisilane and hydrogen chloride with a catalytic amount of aluminum chloride in chloroform solution.展开更多
文摘The complex [closo-3,3-(PPh<sub>3</sub>)<sub>2</sub>-3-H-3,1,2-RhC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]has a rich derivative chemistrythat is currently under active investigation.The resultant compound shows an increasing stabilitythat is often associated with metallocarboranes.This paper deals with the novel and the produc-tion area of carborane complexes of transition metals.The paper indicates that some reactions can easily proceed and the resulting compound hassome new properties and uses.K[18-crown-6][closo-3-Ph<sub>3</sub>P-3-CH<sub>2</sub>Ph-3-Br-3,1,2-RhC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]can be synthesized by the reaction of K[18-crown-6][(Ph<sub>3</sub>P)<sub>2</sub>RhC<sub>2</sub>B<sub>9</sub>H<sub>11</sub>]withbromo-toluene under the condition of dry benzene.IR and <sup>1</sup>H,<sup>11</sup>B,<sup>31</sup>p nuclear magnetic reso-nance and elemental analysis comfirm the structure for this species with one carborane groupbonded to the central metal.
基金Supported by the National Natural Science Foundation of China( No.2 99740 2 9,2 992 5 10 1) and Special Funds forMajor State Basic Research Projects of China( G19990 64 80 0)
文摘Halfsandwich iron dicarbonyl complex [η 5-C5H3(t-Bu)2]Fe(CO)2Cl(1) reacts with 1, 2-dilithium diseleno carborane Li2Se2C2B 10H 10(2) to give a binuclear iron carborane complex [η 5-C5H3(t-Bu)2]2Fe2(CO)3·Se2C2B 10H 10(3). The X-ray diffraction analysis of complex 3 reveals that one of the iron atoms is chiral.
基金Project supported by the Science and Technology Research Project of Key Laboratory of Higher Institutions of Jiangxi Province(No.GJJl 1710)the Science and Technology Research Projects of the Education Department of Jiangxi Province(Nos.GJJ09376 and GJJ10613)+2 种基金the National Natural Science Foundation of China(21361022 and 21261020)the Scientific and Technological Landing Project of Higher Education of Jiangxi Province(No.KJLD12094)the Fourth Point of Specialty Construction College of Education Ministry(No.TS11524)
文摘A new compound [CpCo(Se2C2BIoH9)CH2C(O)C4H30] has been synthesized and characterized by elemental analysis, IR spectroscopy, NMR, MS and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group P21/c with a = 10.9481(10), b = 24.6600(12), c = 25.7430(14) A, β = 100.863(3)°, C42H57B30Co306Se6"CH2C12"0.25H20, Mr = 1722.16, V = 6825.6(8) A3, Dc= 1.676 g/cm3, Z = 1 and F(000) = 3346. The molecular structure shows a 1:1 ratio product of the two reactants of 16e half-sandwich complex CpCo(Se2C2B10H10) and alkyne 1-(2-furyl)-2-propyn-l-one. The hydrogen atom in the B(3) position of CpCo(Se2C2B10HIo) has been activated and migrated to the terminal carbon of 1-(2-furyl)- 2-propyn-l-one to form the B-CH2 unit. The title compound molecules are linked and extended further into a one-dimensional chain through atypical hydrogen bonds.
基金supported by a grant from the Southern University of Science and Technology.
文摘This work describes a general method for the synthesis of a series of sulfenylated and selenylated carboranes at room temperature using readily available iodocarboranes as starting materials via boron-centered carboranyl radicals.Such hypervalent boron radicals are generated by a visible-light-promoted Pd(O)/Pd(I)pathway.They are useful intermediates and can be trapped by disulfides and phenylselenyl chloride for the convenient construction of B-S/Sebonds.
基金supported by the National Natural Science Foundation of China(Nos.22373061,21973057,and 22003034).
文摘Using the experimentally known aromatic icosahedral superatoms I_(h)B_(12)H_(12)2−and D_(5d)1,12-C_(2)B_(10)H_(12)as building blocks and based on extensive density functional theory calculations,we predict herein a series of core–shell superpolyhedral boranes and carboranes in a bottom-up approach,including the high-symmetry Th B_(12)@B_(152)H_(72)2−(2),C2h C_(2)B_(10)@B_(152)H_(72)(3),D_(3d)B_(12)@B_(144)H_(66)(4),I_(h)B_(12)@C_(24)B_(12)0H_(72)2−(6),and D_(5d)C_(2)B_(10)@C_(24)B_(12)0H_(72)(7).More interestingly,the superatom-assembled linear D2h B_(36)H_(32)^(2−)(8),close-packed planar D_(3d)B_(84)H_(60)^(2−)(10),and nearly close-packed core−shell D_(3d)B_(12)@B144H_(6)6(4)can be extended periodically to form the one-dimensional(1D)α-rhombohedral borane nanowire B_(12)H_(10)(Pmmm)(9),two-dimensional(2D)α-rhombohedral monolayer borophane B_(12)H_(6)(P m1)(11),and the experimentally known three-dimensional(3D)α-rhombohedral boron(R m)(12)which can be viewed as an assembly of the monolayer B_(12)H_(6)(11)staggered in vertical direction,setting up a bottom-up strategy to form low-dimensional boron-based nanomaterials from their borane“seeds”via partial or complete dehydrogenations.Detailed bonding analyses indicate that the high stability of these nanostructures originates from the spherical aromaticity of their icosahedral B_(12)or C_(2)B_(10)structural units which possess the universal skeleton electronic configuration of 1S21P61D101F8 following the Wade’s n+1 rule.The infrared(IR)and Raman spectra of the most-concerned neutral B_(12)@B144H_(6)6(4)and C_(2)B_(10)@C_(24)B_(12)0H_(72)(7)are computationally simulated to facilitate their experimental characterizations.
基金supported by the Research Grants Council of the Hong Kong Special Administration Region (SRFS20214S05)。
文摘Though transition metal-catalyzed cage BH methylation has been well documented, catalytic alkylation of cage BH bonds remained elusive because transition metal alkyl complexes are prone to undergo β-H elimination. We report herein a highly efficient 8-aminoquinoline-assisted nickel-catalyzed regioselective cage B(3,4,5,6)-H tetra-alkylation of o-carboranes employing unactivated alkyl bromides as alkylating agents in the absence of any oxidants, leading to the preparation of a class of tetra-alkylated o-carboranes with a broad substrate scope in good to very high yields. This method opens new avenues for oxidant-free, direct, efficient, sustainable, and regioselective multiple B–H alkylation of carboranes via base metal catalysis.
基金supported by the National Natural Science Foundation of China (Nos.22031003,21720102004)the Shanghai Science Technology Committee (No.19DZ2270100).
文摘Herein,we describe the synthesis of a carborane-supported octanuclear palladacycle complex,Pd_(8)(o-C_(2)B_(10)H_(10)CS_(2)CH_(3))_(4)Cl_(4)(CH_(3)CN)_(4)(complex 1),with B(3)-H activations on o-carborane ligand.The substitution reaction of 1 has been explored,and three of its substituted complexes Pd_(8)(o-C_(2)B_(10)H_(10)CS_(2)CH_(3))_(4)Cl_(4)(L)4(L=^(t)BuNC,2;L=C_(5)H_(5)N,3;L=C_(4)H_(8)S,4)have been synthesized.The m-and p-carborane disubstituted ligands m-and p-C_(2)B_(10)H_(10)(CS_(2)CH_(3))_(2)(ligands 5 and 6)as well as their B—H activated carborane complexes[m-C_(2)B_(10)H_(9)(CS_(2)CH_(3))_(2)PdCl](7)and[p-C_(2)B_(10)H_(8)(CS_(2)CH_(3))_(2)][PdCl(^(t)BuNC)]_(2)(8)have also been synthesized by the similar method.All of these complexes have been characterized,including X-ray single crystal diffraction,NMR spectroscopy,IR spectroscopy and elemental analysis methods.
基金The work described in this paper was supported by grants from the Research Grants Council of the Hong Kong Special Administration Region(Nos.404610 and CUHK7/CRF/12G).
文摘The reasons for facile double desilylation of 13-vertex carborane 1,2-Me_(2)Si(CH_(2))_(2)-1,2-C_(2)B_(11)H_(11)(2)are discussed in this article.New 13-and 14-vertex ruthenacarboranes bearing the same-CH_(2)SiMe_(2)CH_(2)-linkage have been prepared and structurally characterized for comparison.Structural analyses of 13-and 14-vertex heteroboranes as well as control experiments suggest that the facile double desilylation of 2 on silica gel can be attributed to the joint actions of several factors involving the high ring-strain of exo five-membered C_(4)Si ring,Lewis acidity of Si atom and Brønsted acidity of silica surface.
基金support from the National Natural Science Foundation of China(Grant No.21771048)the Natural Science Foundation of Zhejiang Provinee(Grant No.LY17B010002).
文摘The steric and electronic properties of A/-heterocyclic carbenes(NHCs)can be modified by the exocyclic substituents at the nitrogen atoms,by 1-3 atoms'replacements of the five-membered imidazolium skeleton and by the changes of the backbones.Herein,we report the usage of nido-C_(2)B_(3) carbora ne anions as the backb ones of NHCs.Stirring the mixture of sec on dary amino o-carbora nes(lb-le),triethyl orthoformate and HBF4-Et2O results in the unexpected cage-opening of o-carboranes to afford the n/do-C_(2)B_(9) carbora ne anions supported A/-heterocyclic carbene precursors(4b-4e).Deprotonation of 4b with sodium hexamethyldisilazide at-78℃ affords the/V-heterocyclic carbene ligand,which was used to form an Au(I)NHC complex(5).DFT calculations revealed a high-lying lone pair orbitals of the carbene ligands,predicting their strong o-donating abilities.
文摘o-Carboryne (1,2-dehydro-o-carborane) is a very useful synthon for the synthesis of a variety of carborane-functionalized molecules. Diels-Alder reaction of o-carboryne with furans gave a series of carborane-fused oxanorbornenes in moderate to high yields using 1-OTf-1,2-C_2B_10H_11 as carboryne precursor. The resultant cycloadducts can undergo hydrogenation, cyclic oxidation, bromination, [4+2]/[2+2] cycloaddition and nucleophilic ring opening reaction to afford a variety of highly functionalized carboranes that may find applications as useful basic units in medicine and materials science.
基金financially supported by International Cooperative Project (Harbin Institute of Technology 2014DFR40370)International Cooperative Project (Wuxi HIT Limited Corporation & Research Institute of New Materials BZ2015024)
文摘In this study, two fluorinated polyurethanes(FPU) containing carborane groups in the main chains were firstly designed and synthesized via the reaction of hexamethylene diisocyanate trimer(HDI trimer) with fluorinated polyesters(CFPETs) having hydroxyl-terminated carborane groups at room temperature. The structures of carborane fluorinated polyesters(CFPETs) and polyurethanes(CFPUs) were characterized by gel permeation chromatography(GPC), Fourier transform infrared(FTIR) spectroscopy and nuclear magnetic resonance(NMR) measurements. The thermal stability, mechanical properties, Shore A hardness, solvent resistance and acid-alkali resistance of the carborane fluorinated polyurethane films were also studied. Thermogravimetric analysis(TGA) tests manifested that the introduction of carborane groups into the main chain of fluorinated polyurethane endowed the obtained fluorinated polyurethane with excellent thermal stability. The thermal decomposition temperature of carborane fluorinated polyurethane(CFPU) increased by 190 °C compared with that of the carborane-free fluorinated polyurethane(FPU). Even at 800 °C, CFPU showed the char yield of 66.5%, which was higher than that of FPU(34.3%). The carborane-containing fluorinated polyurethanes also showed excellent chemical resistance and prominent mechanical property even after the cured films being immersed into Jet aircraft oil or 37% HCl for 168 h or at high temperature(700 °C). It is found that the structural characteristics of carborane group and the compacted structure of CFPU effectively improve the thermal stability, mechanical property, solvent resistance and acid-alkali resistance of the carborane-free fluorinated polyurethane. These excellent properties make CFPU as the useful raw materials to prepare the high temperature resistant coatings or adhesives for automotive engines, engine or fuel tank of aircraft and other equipment working in high-temperature or high concentrations of acid-alkali environments.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.JD-1512)
文摘Carborane bisphenol novolacs (3 and 4) were synthesized in the presence of acid catalyst from carborane bisphenols (5 and 6) and formaldehyde. Further epoxidization of carborane bisphenol novolacs with epichlorohydrin gave carborane bisphenol epoxy novolacs (1 and 2). The molecular weight and epoxy value of obtained resins were determined using the molecular weight of their precursors. The epoxy values of 1 and 2 were 0.48 and 0.52 respectively, higher than the maximum theoretical epoxy value (0.45) of difunctional carborane bisphenol epoxy resins. FTIR and NMR were utilized to characterize 1 and 2. The curing behaviors were also studied by DSC and the optimized curing conditions were obtained. TGA analysis indicated that carborane moiety could shield its adjacent organic structures against initial decomposition. On the other hand, B--H on carborane cage could react with oxygen to form a three-dimensional network linked by B--O--B and B--C bonds, which further blocked the movement of formed radicals and thus the degradation process was inhibited.
基金financially supported by National Key R&D Program of China(No.2016YFB0302105)
文摘o-Carborane-containing poly(hydroxy ethers)(P1, P2 and P3) were synthesized via "advancement reaction" of o-carborane-containing bisphenol(4) and diglycidyl ether of bisphenols(DGEBA and 1). FTIR and 1^H^-, 13^C^-, and 11^ B-NMR were utilized to characterize the obtained polymers. TGA test was conducted under nitrogen and air. It is found that the shielding effect of carborane moiety on its adjacent aromatic structures contributes to high initial decomposition temperatures, while oxygen in air has an adverse effect on the initial decomposition temperature. The oxygen can combine with polymer chain to form peroxide and hydroperoxide groups, which are more reactive during the degradation process. Besides, o-carborane-containing poly(hydroxy ethers) have high char yield at elevated temperatures. The boron atom combines with oxygen from the polymer structure or/and from air, thus to form a three-dimensional network linked with B―O―B and B―C bonds, and retain the polymer weight to a large extent.
基金This work was supported by the National Natural Science Foun-dation of China(Nos.21531002,21720102004,22031003)the Shanghai Science Technology Committee(No.13JC1400600).
文摘We report herein a practical approach for regio-selective B—H/C—H bond activation at azo-substituted carboranes. The reaction proceeded through Iridium(III)-induced selective B—H/C—H bond activations based on an azo directing group. Through this strategy, a series of mononuclear, trinuclear and tetranuclear cyclometalated iridium complexes containing Cp*Ir—B or Cp*Ir—C bonds were successfully isolated in a high yield. In this work, efficient routes are developed through one-pot reactions to prepare polynuclear organometallic complexes.
基金the National Natural Science Foundation of China(No.21901039)the Natural Science Foundation of Jiangsu Province(No.BK20190327)。
文摘Carboranes are a class of polyhedral boron-carbon molecular clusters,they can serve as versatile ligands in stabilizing low-valent main group element compounds,due to their exceptionally thermal and chemical stabilities,easy modifications at the cage carbon vertices,as well as large spherical steric effects.These carborane-based ligands provide interesting opportunities for the synthesis of low-valent main group element compounds with novel structure and reactivity,which indeed enrich the chemistry of low-valent element main group compounds.This review summarizes the recent advances in the chemistry of lowvalent group 13 and group 14 element compounds supported by carborane-based ligands.Achievements and perspectives in this new and flourishing field are discussed in this review.
基金theNationalNaturalScienceFoundationofChina (No .2 992 5 10 1)theMajorStateBasicResearchDevelopmentProgram (No .G19990 64 80 0 )
文摘Metallocene complex Cp tt 2ZrCl 2 (Cp tt =η 5 1,3 t Bu 2 C 5 H 3 ) (1) has been prepared from the reaction of LiCp tt with ZrCl 4 in good yield. Reactions of 1 with dilithium dichalcogenolate o carboranes afforded new type of half sandwich compounds with dichalcogenolate o carboranyl ligands, [Li(THF) 4 ][Cp tt Zr(E 2 C 2 B 10 H 10 ) 2 ] (E=S, 2a; E=Se, 2b) in which only one cyclopentadienyl ring ligand existed. Complexes 1 and 2a were structurally characterized by X ray analyses. In complex 2a, the Zr(IV) ion is η 5 bound to one 1,3 di tert cyclopentadienyl ring and σ bound to four μ 2 sulfur atoms of two dithio carboranes. The zirconium atom and four sulfur atoms form a distorted pyramid. The coordination sphere around the zirconium atom resembles in a piano stool structure with four legs of sulfur atoms and the fulcrum at the zirconium atom.
基金Project supported by the Research Grants Council of the Hong Kong Special Administration Region, National Natural Science Foundation of China and Germany/Hong Kong Joint Research Scheme.
文摘Ligand modifications have played a crucial role in developing new catalyst precursors. A novel class of “constrained-geometry”ligands bearing a carboanion functionality has been developed by linking o-carboranyl and n-ligand together. They offer group 4 metal complexes higher activity in olefin polymerization compared to those with appeoded heteroatom systems. The results show that the [{η^5:σ-Me2A(C5H4)(C2B10H10)}M] moiety remains intact in olefin polymerization and insertion reactions of various unsaturated molecules, and the electron-deficient yet sterically hindered icosahedral carborane does play an important role in the reactions. This article provides an overview of our recent work on this subject.
基金supported by the National Key R&D Program of China (2016YFB0700600)Soft Science Research Project of Guangdong Province (2017B030301013)+2 种基金Shenzhen Science and Technology Research Grant (ZDSYS201707281026184)supported in partial by NSF Grants DMS1721024,DMS1761320,IIS1900473NIH grants GM126189 and GM129004 Bristol-Myers Squibband Pfizer。
文摘Persistent homology is a powerful and novel tool for quantifying the inherent topological features of structure. In this work, we used the persistent homology for the first time to study the closo-carboranes C2Bn-2Hn(n = 5~20) and their parent structures closo-boranes dianions BnHn2-(n = 5~20), where multiple elements are present. All these structures are first investigated with the standard Vitoris-Rips complex. We interpret all barcodes representation and associate them with structural details. By means of average bar length, a linear regression model was established to construct the relationship between persistent homology features and molecular stability, which was expressed by the relative energies. For closo-boranes dianions, we only use B atom set since B and H atoms are in pairs. The average lengths of β0, β1 and β2 bars are used as the features for linear regression, and excellent correlation coefficient(0.977) between the values predicted by persistent homology and those by quantum calculations was achieved. For closo-carboranes, C–B atom set(ignore the differences in the atoms), B atom set and C atom set were considered to get the persistent homology features(since there were only two C atoms in C2Bn-2Hn, only β0 bars were considered), and seven average bar lengths were calculated, respectively. Pearson coefficient of 0.937 was obtained. We found that the stability of carboranes showed a high linear correlation with the characteristics generated from topological bars in H0, H1 and H2. The results show that the topological information generated by persistent homology can be extended and applied to multi-element systems.
基金Nakatani FoundationMinistry of Education,Culture,Sports,Science,and Technology,Japan for Scientific Research,Grant/Award Number:JP21H02001ScientificResearch on Innovative Areas“New Polymeric Materials Based on Element-Blocks”,Grant/Award Numbers:No.2401,JP24102013。
文摘We designed the triad molecule,bis-o-carborane-substituted bis(thienylethynyl)benzene,as a filler for realizing thermochromic luminescent behaviors based on conventional polymer films,such as polystyrene.From the optical measurements,it was found that the triad can show solid-state emission and dual-luminescent properties with variable intensity ratios depending on media.From the mechanistic studies including the experiments with the methyl-substituted model compound,it was revealed that dual emission should be originated from the locally excited and twisted intramolecular charge transfer states,and the latter emission band is significantly enhanced in the solid states.We prepared amorphous films containing variable concentrations of the triad with the spin-coating method and investigated optical properties.It was found that intensity ratios were drastically changed by altering the concentration of the triad.By increasing the proportion of the triad,aggregation occurred,and emission color was apparently varied through the changes in intensity ratios of the dual emission property.Based on the aggregationinduced luminochromic property of the triad,thermochromic luminescence was finally realized by heating the amorphous films.The rational design for obtaining thermochromic luminescent amorphous films is illustrated in this paper.
基金Project (No. 29272040) supported by the National Natural Science Foundation of China
文摘The syntheses of trislanes containing C-monosubstituted o-carborane are described.Hie intermediate compound,2-chloro-2-phenyl-hexamethyltrisilane,was prepared by elimination reaction between 2,2-diphenylhexamethyltrisilane and hydrogen chloride with a catalytic amount of aluminum chloride in chloroform solution.