π-π Stacking, Hydrogen Bonding and Magnetic Coupling Mechanism on a Mono-nuclear Cu^Ⅱ Complex

A new mono-nuclear CuII complex [Cu（DPP）（DP）Br]（ClO4）H2O （DPP = 2-（3,5- dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline, DP = 3,5-dimethyl-1H-pyrazole） has been syn- thesized with 2-（3,5-dimethyl-1H-pyrazol-1-yl）-1,10-phenanthroline and 3,5-dimethyl-1H-pyrazole as ligands, and its crystal structure was determined by X-ray crystallography. The crystal is of monoclinic system, space group P21/c with a = 13.765（2）, b = 17.044（3）, c = 10.9044（16）, β= 97.112（2）°, V = 2538.5（6）3, Z = 4, C22H24BrClCuN6O5, Mr = 631.37, Dc = 1.652 g/cm3, F（000） = 1276 and μ= 2.585 mm-1. In the crystal, DPP functions as a tridentate ligand and CuII ions assume a distorted square pyramidal geometry with Br atom lying on the apex, and at the same time, there is π-π stacking between adjacent complexes, which deals with two 1,10-phenanthroline plane rings. In addition to the π-π stacking, there are C-H···Br non-classic hydrogen bonds between adjacent complexes. The theoretical calculations reveal that the π-π stacking and C-H···Br non-classic hydrogen bond result in a weak anti-ferromagnetic interaction with 2J = -5.34 cm-1 and a weak ferromagnetic 2J = 5.92 cm-1, respectively. The magnetic coupling sign from the π-π stacking could be explained with McConnell I spin-polarization mechanism.

A New Cadmium(Ⅱ) Coordination Polymer Extended through Hydrogen Bonds and π-π Stacking Interactions: Synthesis and Photoluminescence Property

A new coordination polymer, {[Cd(OPY)(tdc)(HO)]·H2 O}n(OPY = 4,4?-(oxybis(4,1-phenylene))dipyridine, H2 tdc = thiophene-2,5-dicarboxylic acid), has been synthesized hydrothermally based on a V-shaped ligand OPY. The structure was fully characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction analysis. In1, two OPY ligands and one water molecule acted as terminal ligands coordinating to Cdcation to form [Cd(OPY)HO]units, which are then linked by tdc2-ligands to generate a one-dimensional chain. Every two adjacent chains linked by extensive O–H···O hydrogen bonds constitute one-dimensional double-chains, and such chains are extended into two-dimensional layers via O–H···N hydrogen bonds. These layers are further connected to form a three-dimensional supramolecular architecture via π-π stacking interactions. In addition, the thermal stability and solid state fluorescence property of 1 were also investigated.

π-π Stacking and Magnetic Coupling Mechanism on a Mono-nuclear Mn(Ⅱ) Complex

A new mono-nuclear Mn（Ⅱ） complex [Mn（MPT）2（NCS）（HOCH3）]ClO4（MPT = 2-methoxyl-1,10-phenanthroline） has been synthesized with 2-methoxyl-1,10-phenanthroline and thiocyanate anion as ligands,and its crystal structure was determined by X-ray crystallography.The crystal data：monoclinic system,space group P21/c with a = 12.8849（17）,b = 15.684（2）,c = 14.2703（19） ,β = 92.126（2）°,V = 2881.9（7） 3,Z = 4,C28H24ClMnN5O7S,Mr = 664.97,Dc = 1.533 g/cm3,F（000） = 1364 and μ = 0.679 mm-1.In the crystal,MPT functions as a bidentate ligand and Mn（Ⅱ） ion assumes a distorted octahedral geometry.In the crystal there are two types of π-π stacking interactions among the adjacent complexes,which involves 1,10-phenanthroline rings.The theoretical calculations reveal that the two types of π-π stacking resulted in a weak anti-ferromagnetic coupling with 2J =-14.68 cm-1 and a weak ferromagnetic coupling with 2J = 0.70 cm-1,respectively.The theoretical calculations also reveal that there are both spin polarization and spin delocalization in the two π-π stacking systems,and the magnetic coupling signs are unable to explain with McConnell I spin-polarization mechanism.

Thermal Stability Improved by π–π Stacking Interactions: Synthesis, Crystal Structure and Thermal Decomposition of Sodium Nitroformate

An energetic salt, sodium nitroformate （NaNF）, was synthesized and characterized by elemental analysis, IR and UV spectra, and its crystal structure was first determined by single crystal X-ray diffraction. The structure exhibits two types of π-π stacking interactions between the nitroformate anions, i e, the parallel-displaced and T-shaped confgurafions. Furthermore, the thermal decomposition mechanism was investigated by DSC, TG-DTG and FTIR techniques. The kinetic parameters of the thermal decomposition were also calculated by using Kissinger＇s and Ozawa-Doyle＇s methods. The results show that NaNF has a good thermal stability, which is attributed to the π-π stacking interactions.

Synthesis and Crystal Structure of a New Copper(II) Complex with 4-Cyanobenzoic Acid

A new Cu（Ⅱ） complex [Cu（4-cba）（1,10-phen）（H2O）2]（NO3） （4-Hcba = 4-cyanobenzoic acid） has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characterized by single-crystal X-ray diffraction. Crystallographic data： C20H16CuN4O7, Mr= 487.91, triclinic, space group PI, a = 7.8420（2）, b = 9.1070（2）, c = 15.1140（6） A, a = 76.889（9）, β = 81.332（11）, γ = 74.844（ 11）°, V = 1009.89（5） A^3, Z = 2, Dc = 1.605 g/cm^3, F（000） = 498, μ = 1.134 mm^-1, the final R = 0.0379 and wR = 0.0865 for 2977 observed reflections with 1 〉 2σ（Ⅰ）. The Cu（Ⅱ） atom is coordinated by two terminal water molecules, one chelating 1,10-phen molecule and one monodentate 4-cba ligand to form a slightly distorted square pyramid. The title complex molecules are connected through hydrogen bonds and π-π stacking interactions to generate a 2D layered network. The thermogravimetric analysis of the title complex has also been discussed.

Crystal Structure and Luminescence of a New Zn(Ⅱ) Complex [Zn(L)(IPP)(H_2O)]·2H_2O Based on Nicotinate Derivative and 1,10-Phenanthroline Derivative

A new Zn（II） complex, [Zn（L）（IPP）（H2O）]＇2H2O（1, H2L = 3-carboxy-l-car- boxymethyl-2-oxidopyridinium and IPP = 2-（1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl）phenol）, was synthesized under hydrothermal conditions and its structure was determined by single-crystal X-ray diffraction. It crystallizes in triclinic, space group Pi with a = 8.5023（17）, b = 9.945（2）, c = 15.573（3） A, a = 95.87（3）, β = 102.56（3）, y = 100.73（3）°, V= 1248.7（4） A3, Z= 2, C27H22N5O9Zn, Mr= 625.87, Dc = 1.665 g/cm^3, F（000） = 642, μ（MoKa） = 1.053 mm^-1, R = 0.0474 and wR = 0.1352. In 1, one L2-, one 1PP and one water molecule coordinate to the same Zn（II） atom to give a discrete complex with two lattice water molecules. Adjacent [Zn（L）（IPP）（H20）].2H20 molecules interact through π-π stacking between two IPP ligands to form a supramolecular chain. The N-H…O and O-H…N hydrogen bonds further stabilize the supramolecular chain structure of 1. The solid state luminescent property of 1 was also studied.

Synthesis and Crystal Structure of 5,7-Dimethoxy-2-phenylquinolin-4-yl Phenyloxy (N-L-Alanine ethyl ester) Phosphoramidate

5,7-Dimethoxy-2-phenylquinolin-4-yl phenyloxy （N-L-alanine ethyl ester） phosphoramidate （C28H29N2O7P, Mr = 536.17） has been synthesized by a facial phosphorylated reaction, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to triclinic, space group P1^-, with a = 11.375（2）, b = 11.591（2）, c = 11.638（2） A^°, α= 109.46（3）, β= 104.58（3）, γ= 100.48（3）°, V = 1339.6（5）A^°^3, Z = 2, Dc = 1.330 g/cm^3,μ = 0.152 mm^-1, F（000） = 564, the final R = 0.0654 and wR = 0.1546. In the crystal structure, the title compound is constructed by a centrosymmetric dimmer unit composed of a pair of π-π stacking diastereoisomers. The compound has a noteworthy feature in the framework, and such units are linked by two equal intermolecular P=O…H-N hydrogen bonds.

Crystal Structure of 2,6-Dihistidine Dimethyl Ester Pyridine Acylamine Monohydrate

The crystal structure of the title compound,C21H25N7O7,has been determined in the orthorhombic space group C222（1） with a=8.993（10）,b=12.149（14）,c=22.20（2）A and Z=4.There exist intramolecular C-H…O and N-H…N hydrogen bonds in the title crystal structure.The intermolecular N-H…N and C-H…O hydrogen bonds together with π-π stacking interactions（face-to-face） link the molecules into an infinite three-dimensional supramolecular network.

Design,Synthesis and Crystal Structure of Two One-dimensional Zigzag Chain-like Compounds

Two one-dimensional chain-like cyanide-bridged compounds, [Fe（Phen）2（CN）2Ni（Cyclam）]（ClO4）2·DMF-2H2O 1 （Cyclam = 1,4,8,11-tetraaza-cyclotetradecane, Phen = 1,10-phenanthroline, and DMF = N,N-dimethylformamide） and [Fe（Phen）2（CN）2Zn（Cyclam）]（PF6）2·CH3CN 2, were prepared by the reaction of [Fe（Phen）2（CN）2]·2H2O with M（Cyclam）^2＋ （M = Ni, Zn）. In complexes 1 and 2, the metal atoms are connected alternatively with CN groups. X-ray structure and IR analyses for 1 and 2 were performed. Structure analysis revealed that both complexes are centrosymmetric and the geometry around each metal atom is an octahedron. The two complexes crystallize in triclinic with space group of P^1-. For 1, a = 10.439（4）, b = 14.976（7）, c = 15.914（8）A,α = 83.168（15）, β = 74.338（15）, γ = 78.023（15）°, V = 2338.3（18）A^3, Z = 2, Mr = 1035.37, Dc = 1.471 g/cm^3, F（000） = 1076,μ = 0.895 mm^-1, the final R = 0.0616 and wR = 0.1414 for 5849 observed reflections （1 〉 2σ（I））. For 2, a = 9.656（6）, b = 15.404（9）, c = 15.822（10）A, α = 78.68（2）, β= 78.917（19）, γ = 77.15（2）°, V = 2223（2）A^3, Z = 2, Mr = 1064.87, Dc = 1.587 g/cm^3, F（000） = 1078,μ = 1.032 mm^-1, the final R = 0.0672 and wR = 0.1595 for 6819 observed reflections （I 〉 2σ（I））.

Preparation and Crystal Structure of 3-(2-Hydroxyphenyl)-6-(4-nitrophenyl)-7H- 1,2,4-triazolo[3,4-b][1,3,4 ]thiadiazine

3-(2-Hydroxyphenyl)-6-(4-nitrophenyl)-7H-1,2,4-triazolo[3,4-b][1,3,4] thiadiazine, C 16H 11N 5O 3S, was prepared by the cyclization of 3-(2-hydroxyphenyl)-4-amino-5-mercapto-1,2,4-triazole with 2-bromo-4-nitroacetophenone. The compound was characterized by means of elemental analysis, IR, 1H NMR, 13C NMR, mass spectrometry, and X-ray diffraction. The compound crystallizes in a monoclinic system with space group C c, a=2.1853(4) nm, b=2.1192(5) nm, c=1.3526(3) nm, β=95.21(2)°, V=6.238(2) nm3 , D calcd.=1.505 Mg/m3, Z=16, F(000)=2916, R 1=0.0501, wR 2=0.0427. A comparison between the crystal structures of 1,2,4-triazolo[3,4-b] [1,3,4] thiadiazine and 1,2,4-triazolo[3,4-b][1,3,4] thiadiazole was made in the structural view. A two-dimensional network is formed by hydrogen bonds and π-π stacking interactions.

Synthesis and Crystal Structure of Diisopropyl Genistein-7-yl Phosphate

Diisopropyl genistein-7-yl phosphate （C21H23O8P, Mr = 434.11） has been synthesized by a facile phosphorylated reaction with genistein and diisopropyl phosphite, and its structure was determined by IR, NMR, HR MS and X-ray single-crystal diffraction. The crystal belongs to monoclinic, space group P21/n, with a = 9.0690（18）, b = 9.0412（18）, c = 26.544（5）, β = 99.44（3）°, V = 2147.0（7） 3, Z = 4, Dc = 1.344 Mg/m3, μ = 0.172 mm-1, F（000） = 912, the final R = 0.0545 and wR = 0.1352. In the crystal structure, the title compound is constructed by both intramolecular （O-H···O=C） and intermolecular （O-H···O=P） hydrogen bonding as well as π-π stacking interaction.

Crystal Structures and Photoluminescence of Two New Tetrazole-based Complexes

The solution reactions of the metal salts with 2,2＇-bipyfidine （2,2＇-bipy） and ethyl tetrazole-5-carboxylate （Hetzc） afforded two new tetrazole-based complexes M（2,2＇-bipy）2（etzc）2 （M=Mn 1, Zn 2）, and their crystal structures were determined by single-crystal X-ray diffraction analyses. Crystallographic data for 1： C28H26MnN12O4, Mr = 649.55, monoclinic, space group C2/c, a= 19.326（15）, b = 11.051（6）, c = 16.388（13）А,β= 117.38（4）° V= 3108（4） А^3, Z= 4, Dc = 1.388 g/cm^3, F（000） = 1340, R = 0.0557 and wR = 0.1269; and those for 2： C28H26ZnN12O4, Mr = 659.98, monoclinic, space group C2/c, a = 19.173（4）, b = 11.006（2）, c = 16.266（4） А, β= 118.11（3）°, V= 3027.4（11） А^3, Z = 4, Dc=1.448 g/cm3, F（000） = 1360, R = 0.0428 and wR = 0.1000. The structures of 1 and 2 are isomorphic and consist of isolated neutral mononuclear units. The metal atoms have highly distorted octahedral coordination environments with two N atoms from two etzc ligands and four N atoms from two 2,2＇-bipy molecules. The isolated mononuclear units are connected by π…π stacking interactions to generate one-dimensional chains. The thermal stability and photoluminescence have also been discussed.

Synthesis and Crystal Structure of (5-Hydroxy-6-methoxybenzofuran-3-yl)-(4-methoxyphenyl)methanone

Compound 1 （5-hydroxy-6-methoxybenzofuran-3-yl）（4-methoxyphenyl）metha- none, C17H1405, as a potential anti-breast cancer agent has been synthesized under microwave irradiation, which was further converted to （5,6-dihydroxybenzofuran-3-yl）（4-methoxyphenyi）me- thanone （2）. The compounds were characterized by MS and NMR spectra. Meanwhile, the crystal of 1 was obtained and determined by X-ray single-crystal diffraction. Crystal data： monoclinic system, space group P2/n, a = 8.908（6）, b = 10.505（7）, c = 15.452（11） A, β = 105.043（9）, V = 1396.4（16） A3, Z = 4, F（000） = 624, Dc = 1.419 g/cm3, p = 0.105 mm-1, R = 0.0513 and wR = 0.1246 for 14459 independent reflections （Rint = 0.0647） and 2488 observed ones （I〉 2σ（/））. lntermolecular O-H...O and π-π stacking interactions contributed to the stability of the structure.

Synthesis and Crystal Structure of [Zn(FcCOO)_2(2,2'-bipy)(H_2O)]_2·H_2O

A novel complex [Zn（FcCOO）2（2,2＇-bipy）（H2O）]2-H2O （Fc = （η^5-C5H5）Fe（η^5-CsH4）, 2,2＇-bipy = 2,2＇-bipyridine） has been synthesized and characterized by elemental analysis, IR and X-ray diffraction. It crystallizes in monoclinic system, space group P21/c with a = 6.8187（4）, b = 21.7155（13）, c = 19.7411（12） A, a = 90, β = 97.7420（10）, γ = 90°, CtaHssFe4Zn2N4O11, Mr = 1413.28, V = 2896.4（3）A^3, Dc = 1.620 g/cm^3, Z = 2, F（000） = 1444,μ（MoKa） = 1.857 mm^-1, R = 0.0523 and wR = 0.0982 for 3219 observed reflections （I 〉 2σ（I））. Structural analysis shows that the zinc atom is coordinated with three oxygen atoms from two ferrocenemonocarboxylates and one water molecule together with two nitrogen atoms from 2,2＇-bipyridine, giving a distorted square-pyramidal coordination geometry. The complex molecules are linked to form an infinite one-dimensional chain by both intermolecular hydrogen bonds and π-π stacking interactions of the bipyridine rings.

Synthesis and Crystal Structure of catena-Poly[bis-(benzimidazole)cobalt(II) μ-Phthalato]

The title polymeric complex [Co（C8H4O4）（C7H6N2）2]n has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group C2/c with a=7.7865（12）, b=20.4215（18）, c=13.4880（14）A°,β=103.298（2）°, V=2087.3（4）A°^3, Mr=459.32, Z=4, Dc=1.462 g/cm^3,μ=0.859 mm^-1, F（000）=940, R=0.0636 and wR=0.1639 for 1278 observed reflections （I〉2σ（I））. The complex assumes a distorted tetrahedral coordination geometry, formed by two phthalate anions and two benzimidazoles （bzim）. The phthalate anions bridge the neighboring Co（Ⅱ） atoms to form the polymeric chains. The centroid distance of 3.471（3）A° between the parallel bzim rings of adjacent polymeric chains suggests the existence of π-π stacking.

Synthesis and Crystal Structure of Dichlorobis-(1-methylimidazoline-2(3H)-thione-S) Cobalt(II)

The reaction of anhydrous cobalt(II) dichloride with 1-methylimidazoline-2(3H)- thione in dichloromethane solution gave the title complex, [Co(C4H6N2S)2Cl2]. X-ray single-crystal analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, a = 13.9707(10), b = 10.0435(7), c = 10.3910(6) ?, β = 91.181(3)o, V = 1457.70(17) ?3, Z = 4, C8H12Cl2N4S2Co, Mr = 358.17, Dc = 1.632 g/cm3, μ = 1.813 mm–1, F(000) = 724, the final R = 0.0710 and wR = 0.1224 for 1549 observed reflections with I > 2σ(I). The Co atom is coordinated by two S atoms from two 1-methylimidazoline-2(3H)-thione ligands and two chloride ions in a slightly distorted tetrahedral geometry. The intramolecular classical hydrogen-bonding interactions involving chloride ions and N–H groups of the heterocyclic thione ligands are observed. The offset π-π stacking interactions between the imidazole rings of adjacent molecules with a face-to-face dis- tance of 3.604 ? are found in the packing diagram.

Synthesis and Crystal Structure of 4-(4,6-Dimethoxylpyrimidin-2-yl)-3-thiourea Carboxylic Acid Ethyl Ester

4-（4,6-Dimethoxyl-pyrimidin-2-yl）-3-thiourea carboxylic acid ethyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at room temperature. The crystal structure was determined by X-ray diffraction analysis. Crystallographic data： C10H14N4O4S, M, = 286.31, monoclinic, space group C2/c with a = 2.5309（3）, b = 0.67682（6）, c = 1.74237（19） nm, β = 114.744（3）°, V= 2.7106（5） nm3, Dc = 1.403 g/cm3, p = 0.225 mm-1, F（000） = 1200, Z= 8, R= 0.0514 and wR= 0.1529.

Synthesis and Crystal Structure of a New Nickel(II) Complex with Unsymmetric Quadridentate Schiff Base Containing Oxime

The title complex, C18H15N3NiO3, has been prepared and characterized by X-ray diffraction analysis. It crystallizes in the monoclinic system, space group Cc with a = 10.939(2), b = 22.909(5), c = 6.907(1) ?, β = 116.75(3)°, V = 1545.7(5) ?, Z = 4, Mr = 380.04, F(000) = 784, Dc = 1.633 g/cm3 and μ(MoKα) = 1.279 mm–1. The structure was refined to R = 0.0472 and wR = 0.0893 for 2571 observed reflections with I > 2σ(I). The absolute structure Flack parameter X is 0.01(2). In this crystal structure, strong face-to-face π-π stacking interactions between adjacent molecules lead to a one-dimensional chain structure.

Synthesis and Crystal Structure of a Co(II) Complex with Schiff Base and Imidazole Ligand

The title compound, [Co（C3H4N2）2（C22H18N2O4）]·5H2O （Mr = 659.56）, has been prepared and its crystal structure was determined by X-ray diffraction method. The crystal belongs to monoclinic, space group P21/n, a = 9.6808（2）, b = 26.7204（5）, c = 12.7993（3） A, β = 100.9340（10）°, V= 3250.75（12） A^3, Z = 4, Dc = 1.348 g/cm^3,μ = 0.586 mm^-1, F（000） = 1380, S = 1.131, R = 0.0689 and wR = 0.1883 for 4782 observed reflections （Ⅰ 〉 2σ（Ⅰ））. The title crystal consists of Co（Ⅱ） complex and lattice water molecules. The Co（Ⅱ） complex assumes a distorted octahedral coordination geometry, formed by one Schiff base dianion phenylenediamine-3-methoxysali-cylaldehyde and two imidazole ligands. The π-π stacking interaction occurs between nearly parallel benzene rings of the neighboring complexes.

Synthesis and Crystal Structure of a Chiral Manganese(Ⅲ) Schiff Base Complex

A chiral salency complex,[Mn（Salency）（H2O）2]（PF6）·2H2O 1（Salency =（R,R）-N,N＇-bis（salicylidene）-1,2-cyclohexanediamine）,has been prepared by the reaction of Mn（CH3COO）3·2H2O with Salency and NH4PF6,and was established by X-ray diffraction techniques.The complex crystallizes in triclinic,space group P1 with a=9.299（8）,b=10.012（8）,c=13.461（11）,α=92.037（15）,β=92.974（12）,γ=93.530（18）°,V=1248.3（18）3,C20H28F6MnN2O6P,Mr = 592.35,Z=2,Dc=1.038 g/cm3,F（000）=608,μ=0.676 mm–1,the final R=0.0651 and wR=0.1880 for 5260 observed reflections with I 2σ（I）.