In this paper, we synthesized nineteen substituent 1-(o-chloro-benzoyl)-3-(phenyl) thiourea derivatives and studied their structure activity relationship, We found that the compounds with electron-withdrawing group (F...In this paper, we synthesized nineteen substituent 1-(o-chloro-benzoyl)-3-(phenyl) thiourea derivatives and studied their structure activity relationship, We found that the compounds with electron-withdrawing group (F) would have higher insecticidal activity.展开更多
Using density functional methods,some properties were studied such as the energies and compositions of frontier molecular orbitals and the atomic charges,which are related to the reactive behavior of thioureas contain...Using density functional methods,some properties were studied such as the energies and compositions of frontier molecular orbitals and the atomic charges,which are related to the reactive behavior of thioureas containing different N-substituent groupings.The calculation results indicate that the N-substituent groupings have significant effect on the flotation performance of thiourea collectors.The order of electron-donating ability is N-propyl-N'-benzyl-thiourea(PBZYTU)>N-propyl-N'-ethyl-thiourea (PETU)>N-propyl-N'-allyl-thiourea(PALTU)>>N-propyl-N'-acetyl-thiourea(PACTU)>N-propyl-N'-ethoxycarbonyl-thiourea (PECTU)>N-propyl-N'-benzoyl-thiourea(PBZOYTU),and the order of feedback-electron-accepting ability is PBZOYTU> PACTU>PECTU>>PALTU>PETU>PBZYTU.This implies that PBZOYTU,PACTU or PECTU can react with copper atoms having(t2g) 6 (eg) 3Cu(II)or t 6e 4Cu(I)configuration on the surfaces of copper sulfide minerals through normal covalent bond and back donation covalent bond,and exhibit excellently collecting performance for copper sulfide minerals.These are consistent with the experimental data reported in the literatures.展开更多
Fifteen N'-(substituted pyrimidin-2-y1)-N-substituted phenoxyacetyl thioureas were synthesized and tested for biological activities. All of them are new compounds and their structures were confirmed by IR. IHNMR. ...Fifteen N'-(substituted pyrimidin-2-y1)-N-substituted phenoxyacetyl thioureas were synthesized and tested for biological activities. All of them are new compounds and their structures were confirmed by IR. IHNMR. MS and elemental analysis. Some of the target compounds showed excellent inhibitory activities against root and stalk of dicotyledon plant (such as radish). and selective on monoctyledon plant (such as rice).展开更多
The title compound Fe(CH4N2S)2Cl22(C11H6N2O) (Mr = 643.35) has been prepared and its crystal structure was determined by X-ray diffraction method with the following data: triclinic, space group P1, a = 7.3742(10), b =...The title compound Fe(CH4N2S)2Cl22(C11H6N2O) (Mr = 643.35) has been prepared and its crystal structure was determined by X-ray diffraction method with the following data: triclinic, space group P1, a = 7.3742(10), b = 13.0427(12), c = 15.215(2) , a = 88.969(12), b = 78.004(12), g = 79.689(11)o, V = 1408.1(3) 3, Z = 2, Dx = 1.517 g/cm3, m = 0.912 mm-1 and F(000) = 656. The final R = 0.030 and wR = 0.078 for 4070 observed reflections (I > 2s(I)), and R = 0.064 and wR = 0.091 for 5516 independent ones. The crystal consists of tetrahedral Fe(II) complex and hydrogen bonded 4,5-diazafluoren-9-one (dafone). The carbonyl bridge in dafone distorts the bipyridine moiety and results in the longer N…N separation of 3.071(3) and 3.061(3) ? There exists an extensive intermolecular hydrogen bond network in the crystal, and p-p stacking is observed between the neighboring dafone rings.展开更多
The new title compound N-（5-（4-chloro-2-（trifluoromethyl）phenyl）furan-2-carbon-yl）- N＇-（4,6-dimethylpyrimidin-2-yl）thiourea （C19H14C1F3N4O2S） has been synthesized, and its crystal structure and biological b...The new title compound N-（5-（4-chloro-2-（trifluoromethyl）phenyl）furan-2-carbon-yl）- N＇-（4,6-dimethylpyrimidin-2-yl）thiourea （C19H14C1F3N4O2S） has been synthesized, and its crystal structure and biological behaviors were studied. The title compound crystallizes in the monoclinic system, space group P21/c with a = 7.932（5）, b = 33.46（2）, c = 7.556（5） A, β = 98.058（9）°, V = 1986（2） A^3 Mr = 454.85, Z = 4, Dc = 1.521 g/cm^3, μ = 0.349 mm^-1 and F（000） = 928. The structure was solved by direct methods and refined to R = 0.0724 and wR= 0.1429 for 3494 observed reflections （I 〉 2σ（I））. Intermolecular hydrogen bonds along the b axis together with the continuous π-π interactions construct the three-dimensional architecture of the title compound. The preliminary biological tests show definite herbicidalactivity for the title compound.展开更多
The linear potential sweep voltammetry and electrochemical methods were used to study the mechanism and kinetics of gold dissolution in thiourea solution in the absence and presence of sodium sulphite.The results show...The linear potential sweep voltammetry and electrochemical methods were used to study the mechanism and kinetics of gold dissolution in thiourea solution in the absence and presence of sodium sulphite.The results show that in the absence of sodium sulfite the dissolution rate of gold in thiourea solution is relatively slow and it increases with the increase of the concentration of thiourea and decreases with pH. Thiourea is easily oxidized to formamidine disulphide, which reduces the leaching efficiency and increases reagent consumption. In the presence of sodium sulphite, the effective concentration of thiourea is increased and the dissolution rate of gold in thiourea solution is greatly increased. The activation energy required for gold dissolution in thiourea solution with sodium sulphite is 20.9 kJ·mol -1 which is much lower than 55.0 kJ·mol -1 in the absence of sodium sulphite. It is evident that sodium sulphite has a significant effect on the electrochemical reaction kinetics of gold in thiourea solution.展开更多
Raman spectroscopic studies on thiourea (TU) in highly acidic media (e. g. >3 mol/L HC1O4) show that TU as a solution species is protonated through its sulphur atom and forms complex with anions. However, as an ads...Raman spectroscopic studies on thiourea (TU) in highly acidic media (e. g. >3 mol/L HC1O4) show that TU as a solution species is protonated through its sulphur atom and forms complex with anions. However, as an adsorbed species, TU is protonated via the nitrogen atom and adsorbed at the silver electrode surface through the sulphur atom. The distinct effects of pH and anions of the solution on the surface enhanced Raman (SER) spectra of TU were investigated. In acidic and neutral solutions, TU is coadsorbed with anions through its NH3+ and - NH2 groups respectively.展开更多
1-（3-Fluorobenzoyl）-3-（4-trifluoromethylphenyl）thiourea, C15H10F4N2OS, has been synthesized firstly and determined by single-crystal X-ray diffraction analysis. The title compound crystallizes in monoclinic system...1-（3-Fluorobenzoyl）-3-（4-trifluoromethylphenyl）thiourea, C15H10F4N2OS, has been synthesized firstly and determined by single-crystal X-ray diffraction analysis. The title compound crystallizes in monoclinic system, space group C2/c with a = 31.87（3）, b = 7.705（9）, c = 12.591（14） A°, b = 106.06（2）°, V = 2971（6） A°^3, Z = 8, Dc=1.530 g·cm^-1, F（000） = 1392, m = 0.266 mm^–1, S = 1.06, the final R = 0.070 and w R（I 〉 2s（I）） = 0.249. The crystal structure revealed that the carbonyl thiourea unit in the determined compound was mostly planar due in part to the formation of intramolecular N–H···O=C and C–H···S=C hydrogen bonds that form two S（6） rings. The intermolecular contacts of the crystal structure have been preformed based on the Hirshfeld surface and their associated 2D fingerprint plots. In the packing diagram of the synthesized compound, the C=S group formed two types of intermolecular hydrogen bonds by the H–N（C=O） group and the H–C of the phenyl ring, respectively, and they formed R2^2（8） and R2^2（14） ring motifs, respectively. The crystal packing form was also stabilized by the intermolecular hydrogen bonds C–H···O（1–x, y, 0.5–z） with the R2^2（10） ring motifs. In addition, supramolecular layers sustained by π-π stacking interactions（between the C（2）～C（7） rings with the C（10）～C（15） rings） are formed in the crystal structure of the title compound. The electronic and reactivity were assessed by the natural bond orbital（NBO） analysis in this study.展开更多
N-4-（bromobutanoyl）-N＇-（o-, m- and p-tolyl）thioureas 3a, 3b and 3c respectively, were synthesized by the reaction of 4-bromobutanoylisothiocyanate with p-, m- and o-toludine. The products were characterized by IR...N-4-（bromobutanoyl）-N＇-（o-, m- and p-tolyl）thioureas 3a, 3b and 3c respectively, were synthesized by the reaction of 4-bromobutanoylisothiocyanate with p-, m- and o-toludine. The products were characterized by IR, and NMR spectroscopic techniques. The two carbonoylthiourea isomers N-（4-bromobutanoyl）-N＇-（3-methylphenyl）thiourea （3b） and N-（4-bromobutanoyl）-N＇-（4- methylphenyl）thiourea （3c） were obtained in crystalline form by recrystallization from DMSO. X- ray crystallographic studies showed that both compounds 3b and 3c crystallize in triclinic system with space group ofPi. The molecules adopt trans-cis configuration with respect to the positions of 4-bromobutanoyl and tolyl groups respectively, against the thiono C=S bond across their C-N bonds The configuration is attributed by the intrahydrogen bond between the carbonyl oxygen and amide hydrogen atoms. Both crystal structures are stabilized by N-H…S intermolecular hydrogen bonds to form dimers and arranged along the b axis.展开更多
Synthesis and antibacterial activity of some novel urea and thiourea derivatives (8a - 8k, 9a - 9f) of anacardic acid prepared from commercially available anacardic acid which is obtained from natural product Cashew N...Synthesis and antibacterial activity of some novel urea and thiourea derivatives (8a - 8k, 9a - 9f) of anacardic acid prepared from commercially available anacardic acid which is obtained from natural product Cashew Nut Shell Liquid (CNSL). Compounds (8a - 8k, 9a - 9f) were tested for Gram positive and Gram negative bacterial cultures. Most of the compounds were showed active compared with standard drug ampicilline.展开更多
A copper（Ⅱ） complex Cu（L）2（NO3）2 constructed by the L （L = N-（4,6-dimethoxylpyrimidin）-N＇-（ethoxycarbonyl）thiourea） ligand crystallizes in monoclinic, space group C2/c with a = 16.2416（16）, b = 9.1385...A copper（Ⅱ） complex Cu（L）2（NO3）2 constructed by the L （L = N-（4,6-dimethoxylpyrimidin）-N＇-（ethoxycarbonyl）thiourea） ligand crystallizes in monoclinic, space group C2/c with a = 16.2416（16）, b = 9.1385（7）, c = 22.0008（18） A, β = 108.077（2）°, V = 3104.3（5） A^3, Dc = 1.627 g/cm^3, Z = 4, C20H28CuN10O14S2, Mr = 760.18,μ（MoKa） = 0.920 mm^-1, F（000） = 1564, R = 0.0471 and wR = 0.1284 for 2239 observed reflections （I 〉 2σ（I））. X-ray diffraction shows the existence of weak complementary intramolecular N-H...O （DA） hydrogen bonds which further strengthen the coordination from the two L ligands with the Cu（Ⅱ） ion, intermolecular C-H...O hydrogen bonds and weak π...π stacking interactions, leading to the formation of a multi-dimensional supramolecular network.展开更多
Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration ...Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies（IE） of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondynamic polarization studies revealed that thiourea are mixed-type inhibitor that mainly restrains the anodic process.展开更多
An algorithm has been introduced to calculate molecular bond polarizabilities of thiourea, which supply essential electronic information about the nonresonant Raman excited virtual states. The main dynamical behaviour...An algorithm has been introduced to calculate molecular bond polarizabilities of thiourea, which supply essential electronic information about the nonresonant Raman excited virtual states. The main dynamical behaviour of the excited virtual states of thiourea is that the Raman excited electrons tend to flow to the N-H bonds and C-N bonds from the S-C bonds because of the electronic repulsion effect. The difference in Raman excited electron relaxation time of thiourea under 514.5-nm and 325-nm excitations has been observed, which quantitatively shows that the Raman scattering process is dependent on the wavelength of the pumping laser. Finally, the distribution of the electrons at the final stage of relaxation is given out through the comparison between the bond electronic densities of the ground states and the bond polarizabilities after deexcitation.展开更多
Efficient polymer supported synthesis of multi-substituted pyrimidine-4-one derivatives was described. Target products were produced from fluorenylmethoxycarbonyl（Fmoc） protected β-amino acid loaded on hydro- xymet...Efficient polymer supported synthesis of multi-substituted pyrimidine-4-one derivatives was described. Target products were produced from fluorenylmethoxycarbonyl（Fmoc） protected β-amino acid loaded on hydro- xymethyl resin through deprotection, N-alkylation, guanidine formation, and cleavage of 2,2,4,6,7-pentamethyl dihy-drobenzofuran-sulfonyl（Pbf） by trifluoracetic acid（TFA） followed with cyclization. The procedure has the advantages of easy operation, mild reaction conditions, and forming multiple substituents.展开更多
文摘In this paper, we synthesized nineteen substituent 1-(o-chloro-benzoyl)-3-(phenyl) thiourea derivatives and studied their structure activity relationship, We found that the compounds with electron-withdrawing group (F) would have higher insecticidal activity.
基金Project(50604016)supported by the National Natural Science Foundation of ChinaProject(2007B52)supported by the Foundation for the Author of National Excellent Doctoral Dissertation of China+3 种基金Project(NCET-08-0568)supported by the Program for New Century Excellent Talents in Chinese UniversityProject(2007CB613602)supported by the National Basic Research Program of ChinaProject(2007AA06Z122)supported by the National High-tech Research and Development Program of ChinaProject(2007BAB22B01)supported by the National Science and Technology Support Project of China
文摘Using density functional methods,some properties were studied such as the energies and compositions of frontier molecular orbitals and the atomic charges,which are related to the reactive behavior of thioureas containing different N-substituent groupings.The calculation results indicate that the N-substituent groupings have significant effect on the flotation performance of thiourea collectors.The order of electron-donating ability is N-propyl-N'-benzyl-thiourea(PBZYTU)>N-propyl-N'-ethyl-thiourea (PETU)>N-propyl-N'-allyl-thiourea(PALTU)>>N-propyl-N'-acetyl-thiourea(PACTU)>N-propyl-N'-ethoxycarbonyl-thiourea (PECTU)>N-propyl-N'-benzoyl-thiourea(PBZOYTU),and the order of feedback-electron-accepting ability is PBZOYTU> PACTU>PECTU>>PALTU>PETU>PBZYTU.This implies that PBZOYTU,PACTU or PECTU can react with copper atoms having(t2g) 6 (eg) 3Cu(II)or t 6e 4Cu(I)configuration on the surfaces of copper sulfide minerals through normal covalent bond and back donation covalent bond,and exhibit excellently collecting performance for copper sulfide minerals.These are consistent with the experimental data reported in the literatures.
文摘Fifteen N'-(substituted pyrimidin-2-y1)-N-substituted phenoxyacetyl thioureas were synthesized and tested for biological activities. All of them are new compounds and their structures were confirmed by IR. IHNMR. MS and elemental analysis. Some of the target compounds showed excellent inhibitory activities against root and stalk of dicotyledon plant (such as radish). and selective on monoctyledon plant (such as rice).
基金This work was supported by the National Natural Science Foundation of China (29973036)
文摘The title compound Fe(CH4N2S)2Cl22(C11H6N2O) (Mr = 643.35) has been prepared and its crystal structure was determined by X-ray diffraction method with the following data: triclinic, space group P1, a = 7.3742(10), b = 13.0427(12), c = 15.215(2) , a = 88.969(12), b = 78.004(12), g = 79.689(11)o, V = 1408.1(3) 3, Z = 2, Dx = 1.517 g/cm3, m = 0.912 mm-1 and F(000) = 656. The final R = 0.030 and wR = 0.078 for 4070 observed reflections (I > 2s(I)), and R = 0.064 and wR = 0.091 for 5516 independent ones. The crystal consists of tetrahedral Fe(II) complex and hydrogen bonded 4,5-diazafluoren-9-one (dafone). The carbonyl bridge in dafone distorts the bipyridine moiety and results in the longer N…N separation of 3.071(3) and 3.061(3) ? There exists an extensive intermolecular hydrogen bond network in the crystal, and p-p stacking is observed between the neighboring dafone rings.
基金This work was sponsored by NNSFC (No. 20672073)Shanghai Leading Academic Discipline Project (No. T0402)
文摘The new title compound N-（5-（4-chloro-2-（trifluoromethyl）phenyl）furan-2-carbon-yl）- N＇-（4,6-dimethylpyrimidin-2-yl）thiourea （C19H14C1F3N4O2S） has been synthesized, and its crystal structure and biological behaviors were studied. The title compound crystallizes in the monoclinic system, space group P21/c with a = 7.932（5）, b = 33.46（2）, c = 7.556（5） A, β = 98.058（9）°, V = 1986（2） A^3 Mr = 454.85, Z = 4, Dc = 1.521 g/cm^3, μ = 0.349 mm^-1 and F（000） = 928. The structure was solved by direct methods and refined to R = 0.0724 and wR= 0.1429 for 3494 observed reflections （I 〉 2σ（I））. Intermolecular hydrogen bonds along the b axis together with the continuous π-π interactions construct the three-dimensional architecture of the title compound. The preliminary biological tests show definite herbicidalactivity for the title compound.
文摘The linear potential sweep voltammetry and electrochemical methods were used to study the mechanism and kinetics of gold dissolution in thiourea solution in the absence and presence of sodium sulphite.The results show that in the absence of sodium sulfite the dissolution rate of gold in thiourea solution is relatively slow and it increases with the increase of the concentration of thiourea and decreases with pH. Thiourea is easily oxidized to formamidine disulphide, which reduces the leaching efficiency and increases reagent consumption. In the presence of sodium sulphite, the effective concentration of thiourea is increased and the dissolution rate of gold in thiourea solution is greatly increased. The activation energy required for gold dissolution in thiourea solution with sodium sulphite is 20.9 kJ·mol -1 which is much lower than 55.0 kJ·mol -1 in the absence of sodium sulphite. It is evident that sodium sulphite has a significant effect on the electrochemical reaction kinetics of gold in thiourea solution.
文摘Raman spectroscopic studies on thiourea (TU) in highly acidic media (e. g. >3 mol/L HC1O4) show that TU as a solution species is protonated through its sulphur atom and forms complex with anions. However, as an adsorbed species, TU is protonated via the nitrogen atom and adsorbed at the silver electrode surface through the sulphur atom. The distinct effects of pH and anions of the solution on the surface enhanced Raman (SER) spectra of TU were investigated. In acidic and neutral solutions, TU is coadsorbed with anions through its NH3+ and - NH2 groups respectively.
基金supported by the Science and Technology Program of Shaanxi Province,China(No.2013K02-25)the Science and Technology Program of Xi’an,China(No.NC1404)+1 种基金the Science and Technology Research and Development Program of Shaanxi Province,China(No.14JF025)the college students innovative training program of Northwest University,China(No.2017214)
文摘1-（3-Fluorobenzoyl）-3-（4-trifluoromethylphenyl）thiourea, C15H10F4N2OS, has been synthesized firstly and determined by single-crystal X-ray diffraction analysis. The title compound crystallizes in monoclinic system, space group C2/c with a = 31.87（3）, b = 7.705（9）, c = 12.591（14） A°, b = 106.06（2）°, V = 2971（6） A°^3, Z = 8, Dc=1.530 g·cm^-1, F（000） = 1392, m = 0.266 mm^–1, S = 1.06, the final R = 0.070 and w R（I 〉 2s（I）） = 0.249. The crystal structure revealed that the carbonyl thiourea unit in the determined compound was mostly planar due in part to the formation of intramolecular N–H···O=C and C–H···S=C hydrogen bonds that form two S（6） rings. The intermolecular contacts of the crystal structure have been preformed based on the Hirshfeld surface and their associated 2D fingerprint plots. In the packing diagram of the synthesized compound, the C=S group formed two types of intermolecular hydrogen bonds by the H–N（C=O） group and the H–C of the phenyl ring, respectively, and they formed R2^2（8） and R2^2（14） ring motifs, respectively. The crystal packing form was also stabilized by the intermolecular hydrogen bonds C–H···O（1–x, y, 0.5–z） with the R2^2（10） ring motifs. In addition, supramolecular layers sustained by π-π stacking interactions（between the C（2）～C（7） rings with the C（10）～C（15） rings） are formed in the crystal structure of the title compound. The electronic and reactivity were assessed by the natural bond orbital（NBO） analysis in this study.
基金the Ministry of Higher Education of Malaysia and Universiti Kebangsaan Malaysia for the research grant DIP-2014-016 and FRGS/1/2013/ST01/UKM/03/4the Ministry of Higher Education of Libya for the scholarship
文摘N-4-（bromobutanoyl）-N＇-（o-, m- and p-tolyl）thioureas 3a, 3b and 3c respectively, were synthesized by the reaction of 4-bromobutanoylisothiocyanate with p-, m- and o-toludine. The products were characterized by IR, and NMR spectroscopic techniques. The two carbonoylthiourea isomers N-（4-bromobutanoyl）-N＇-（3-methylphenyl）thiourea （3b） and N-（4-bromobutanoyl）-N＇-（4- methylphenyl）thiourea （3c） were obtained in crystalline form by recrystallization from DMSO. X- ray crystallographic studies showed that both compounds 3b and 3c crystallize in triclinic system with space group ofPi. The molecules adopt trans-cis configuration with respect to the positions of 4-bromobutanoyl and tolyl groups respectively, against the thiono C=S bond across their C-N bonds The configuration is attributed by the intrahydrogen bond between the carbonyl oxygen and amide hydrogen atoms. Both crystal structures are stabilized by N-H…S intermolecular hydrogen bonds to form dimers and arranged along the b axis.
文摘Synthesis and antibacterial activity of some novel urea and thiourea derivatives (8a - 8k, 9a - 9f) of anacardic acid prepared from commercially available anacardic acid which is obtained from natural product Cashew Nut Shell Liquid (CNSL). Compounds (8a - 8k, 9a - 9f) were tested for Gram positive and Gram negative bacterial cultures. Most of the compounds were showed active compared with standard drug ampicilline.
基金the National Natural Science Foundation of China (No.20571060)Education Committee of Shaanxi Province (05JK294)Xi'an Scientific and Technical Plan Project (No. YF07106)
文摘A copper（Ⅱ） complex Cu（L）2（NO3）2 constructed by the L （L = N-（4,6-dimethoxylpyrimidin）-N＇-（ethoxycarbonyl）thiourea） ligand crystallizes in monoclinic, space group C2/c with a = 16.2416（16）, b = 9.1385（7）, c = 22.0008（18） A, β = 108.077（2）°, V = 3104.3（5） A^3, Dc = 1.627 g/cm^3, Z = 4, C20H28CuN10O14S2, Mr = 760.18,μ（MoKa） = 0.920 mm^-1, F（000） = 1564, R = 0.0471 and wR = 0.1284 for 2239 observed reflections （I 〉 2σ（I））. X-ray diffraction shows the existence of weak complementary intramolecular N-H...O （DA） hydrogen bonds which further strengthen the coordination from the two L ligands with the Cu（Ⅱ） ion, intermolecular C-H...O hydrogen bonds and weak π...π stacking interactions, leading to the formation of a multi-dimensional supramolecular network.
文摘Corrosion monitoring techniques were performed on X7O steel in saline solution saturated with CO2 with and without thiourea additives within the concentration range 5-25 mg/L. It was found that when the concentration of the inhibitors were increased, the inhibitor efficiencies（IE） of thiourea varied with solution temperature and immersion time. The results indicated that thiourea had the highest inhibition efficiency. The potentiondynamic polarization studies revealed that thiourea are mixed-type inhibitor that mainly restrains the anodic process.
基金supported by the National Science and Technology Major Project (Grant No. ZX06901)
文摘An algorithm has been introduced to calculate molecular bond polarizabilities of thiourea, which supply essential electronic information about the nonresonant Raman excited virtual states. The main dynamical behaviour of the excited virtual states of thiourea is that the Raman excited electrons tend to flow to the N-H bonds and C-N bonds from the S-C bonds because of the electronic repulsion effect. The difference in Raman excited electron relaxation time of thiourea under 514.5-nm and 325-nm excitations has been observed, which quantitatively shows that the Raman scattering process is dependent on the wavelength of the pumping laser. Finally, the distribution of the electrons at the final stage of relaxation is given out through the comparison between the bond electronic densities of the ground states and the bond polarizabilities after deexcitation.
基金Supported by the Scientific Forefront and Interdisciplinary Innovation Project of Jilin UniversityChina(No.421031531412)+1 种基金the Jilin Provincial Research Foundation for Basic Research China(No.3D109K856604)
文摘Efficient polymer supported synthesis of multi-substituted pyrimidine-4-one derivatives was described. Target products were produced from fluorenylmethoxycarbonyl（Fmoc） protected β-amino acid loaded on hydro- xymethyl resin through deprotection, N-alkylation, guanidine formation, and cleavage of 2,2,4,6,7-pentamethyl dihy-drobenzofuran-sulfonyl（Pbf） by trifluoracetic acid（TFA） followed with cyclization. The procedure has the advantages of easy operation, mild reaction conditions, and forming multiple substituents.
