A monodispersed latex from styrene(St), methyl methacrylate(MMA) and acrylic acid(AA) was synthesized with the soap free emulsion polymerization, and the formation of colloidal crystal by evaporating the water of the ...A monodispersed latex from styrene(St), methyl methacrylate(MMA) and acrylic acid(AA) was synthesized with the soap free emulsion polymerization, and the formation of colloidal crystal by evaporating the water of the latex was investigated. It has been confirmed that there exist two array manners, i.e., hexagonal and square array, and two packing modes, i.e., hexagonal packing and face-centered cubic packing in the forming process of colloidal crystals. The square array originated from the dislocation of the particle in the hexagonal array, the area of it depends on the temperature in the forming process. At a lower temperature such as at 0 ℃, relatively large areas of square array were observed in the formed colloidal crystal.展开更多
Simultaneously achieving room-temperature phosphorescence(RTP) and multiple-stimuli responsiveness in a single-component system is of significance but remains challenging. Crystallization has been recognized to be a w...Simultaneously achieving room-temperature phosphorescence(RTP) and multiple-stimuli responsiveness in a single-component system is of significance but remains challenging. Crystallization has been recognized to be a workable strategy to fulfill the above task. However, how the molecular packing mode affects the intersystem crossing and RTP lifetime concurrently remains unclear so far. Herein, four economic small-molecular compounds, analogues of the famous drug raloxifene(RALO), are facilely synthesized and further explored as neat single-component and stimuli-responsive RTP emitters via crystallization engineering. Thanks to their simple structures and high ease to crystallize, these raloxifene analogues function as models to clarify the important role of molecular packing in the RTP and stimuliresponsiveness properties. Thorough combination of the single-crystal structure analysis and theoretical calculations clearly manifests that the tight antiparallel molecular packing mode is the key point to their RTP behaviors. Interestingly, harnessing the controllable and reversible phase transitions of the two polymorphs of RALO-OAc driven by mechanical force, solvent vapor, and heat, a single-component multilevel stimuli-responsive platform with tunable emission color is established and further exploited for optical information encryption. This work would shed light on the rational design of multi-stimuli responsive RTP systems based on single-component organics.展开更多
One-pot three component reaction was used to synthesize 1,4,5-trisubstituted 1,2,3-triazole(A) from the corresponding acid chloride, benzyl azide and 1-copper(I) phenylethyne. The molecular structure was determined by...One-pot three component reaction was used to synthesize 1,4,5-trisubstituted 1,2,3-triazole(A) from the corresponding acid chloride, benzyl azide and 1-copper(I) phenylethyne. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the orthorhombic space group Pbca, a = 14.9815(14), b = 9.6496(10), c = 25.528(2) A, Z = 8. Furthermore, crystal packing demonstrated a molecular wall-like structure based on supramolecular chains of A, stabilized by CH···O, CH···Br, N···C and CH···π interactions. Molecular geometry in the ground state has been determined by density functional theory(DFT) by B3LYP/6-311G* basis set and compared with the experimental data. The computed vibrational frequencies are compared with the experimental FT-IR data and frontier molecular orbital analyses were performed at the same level of theory. Theoretical parameters are in good agreement with the corresponding X-ray diffraction values.展开更多
Quantitative oxygen detection is of great importance in biological fields,complex environments,and chemical process engineering.Due to the high sensitivity and rapid response of long-lived phosphorescence to oxygen,pu...Quantitative oxygen detection is of great importance in biological fields,complex environments,and chemical process engineering.Due to the high sensitivity and rapid response of long-lived phosphorescence to oxygen,pure organic room-temperature phosphorescence(RTP)for oxygen detection has recently attracted considerable interest.However,to simultaneously achieve ultralong phosphorescence at room temperature and quantitative oxygen detection from pure organic crystals is difficult.Tight packing to restrict nonradiative decay is not apt to allow oxygen diffusion for sensing.Reported herein is an exceptional example,that is,a crystal of simple carbazole molecules that bridges with an ethoxysilane(DCzC2OSi)and is capable of oxygen sensing with remarkable sensitivity.Photophysical studies and single-crystal structure analysis reveal that DCzC2OSi crystals display ultralong RTP and suitable oxygen diffusion channels from its butterfly-like tetrahedron geometry.Further comparisons with the crystals of CzC2OH and DCzSi verify the important roles of silicon and ethoxy groups of DCzC2OSi for both enhanced phosphorescence lifetime and oxygen sensitivity.When the crystals of DCzC2OSi were doped into polymer,the lifetime-based oxygen sensor exhibited high KSV(5.308 kPa^(−1))with full reversibility,which is attractive for the development of practical oxygen sensors from pure organic crystals.展开更多
A new one-dimensional mixed-valence Cu（Ⅰ）/Cu（Ⅱ） complex [Cu（bipy）（Me2dtc）CuI2]n 1 （bipy = 2,2′-bipyridine and Me2dtc = N,N-dimethyldithiocarbamate） has been synthesized under solution condition, and chara...A new one-dimensional mixed-valence Cu（Ⅰ）/Cu（Ⅱ） complex [Cu（bipy）（Me2dtc）CuI2]n 1 （bipy = 2,2′-bipyridine and Me2dtc = N,N-dimethyldithiocarbamate） has been synthesized under solution condition, and characterized by elemental analysis, IR spectrum, single-crystal X-ray diffraction and magnetic property. The crystal belongs to the tetragonal system, space group P4122 with a = b = 11.6504（16）, c = 13.466（3） A, V = 1827.8（5） A^3, Z = 4, Dc = 2.389 g/cm^3, Mr = 657.27, λ（MoKa） = 0.71073 , μ = 5.931 mm·1, F（000） = 1236, the final R = 0.0483 and wR = 0.1245. A total of 2102 unique reflections were collected, of which 2009 with I 〉 2σ（I） were observed. 1 consists of polymeric [Cu^II2]nn^- anions and [Cu^II（bipy）（Me2dtc）]^＋ cations. It is interesting that the cations of 1 interact through π-π stacking interactions after rotating 90° to form one-dimensional chains parallel to the anion chains. The magnetic study indicates antiferromagnetic behavior for this complex.展开更多
A new mononuclear Cu（Ⅱ） dithiocarbamate complex CuI（prdtc）（phen） 1 （prdtc = N-pyrrolidinyldithiocarbamate, phen = 1,10-phenanthroline） was synthesized and characterized by elemental analysis, IR spectrum, and...A new mononuclear Cu（Ⅱ） dithiocarbamate complex CuI（prdtc）（phen） 1 （prdtc = N-pyrrolidinyldithiocarbamate, phen = 1,10-phenanthroline） was synthesized and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 8.7110（9）, b = 14.7143（14）, c = 14.8507（15） A, β = 109.721（6）°, V = 1791.9（3） A3, Z = 4, Dc = 1.916 g/cm3, CI7H16CulN3S2, Mr = 516.89, λ（MoKa） = 0.71073A,μ = 3.178 mm^-1, F（000） = 1012, the final R = 0.0369 and wR = 0.0987. A total of 4082 unique reflections were collected, of which 2916 with I 〉 2σ（I） were observed. The Cu（Ⅱ） atom is five-coordinated in a distorted square-pyramidal geometry by one I atom in the apical position, two S atoms from a prdtc ligand and two N atoms from a phen ligand in the basal plane. There exist face-to-face aromatic π-π stacking interactions between adjacent phen ligands stabilizing the structure and making the complex assemble into a 1D structure along the a axis. It can be concluded that the difference of the dtc flexibility and reaction conditions result in the structural difference between complex 1 and CuI（dmdtc）（phen） （dmdtc = N, N-dimethyldithiocarbamate）.展开更多
Two new organic crystals of 2,8-bisthienyldibenzothiophene（BTDT） and 2,8-bis-dithienyldibenzothiophene（BDTDT） compounds were successfully obtained.The change of end-capped group from thiophene to dithiophene cause...Two new organic crystals of 2,8-bisthienyldibenzothiophene（BTDT） and 2,8-bis-dithienyldibenzothiophene（BDTDT） compounds were successfully obtained.The change of end-capped group from thiophene to dithiophene causes big differences in molecular packing and carrier-transport property.The adjacent molecules of compound BTDT adopt face-to-face π stacking and exhibit two-dimensional interchain interactions.On the contrary,BDTDT molecules are arranged in an edge-to-face motif and show mainly one-dimensional interacting character.The packing mode exerts dramatic effect on the carrier-transport property.The crystal of BTDT belongs to the orthorhombic system,space group P21212 with a = 20.1427（11）,b = 4.6016（3）,c = 8.6340（5） ,V = 800.27（8） 3,Z = 2,Dc = 1.446 g/cm3,F（000） = 360,S = 1.019,the final R = 0.0491 and wR = 0.0960 for 1605 reflections with I 2σ（I）.The crystal of BDTDT belongs to the orthorhombic system,space group P212121 with a = 7.2636（15）,b = 25.359（5）,c = 25.359 ？,V = 4670.9（14） ？3,Z = 8,Dc = 1.458 g/cm3,F（000） = 2112,S = 0.880,the final R = 0.0597 and wR = 0.1318 for 8047 reflections with I 2σ（I）.展开更多
Based on three rationally designed pyrrole-appended o-carborane derivatives,we present that fluores-cence properties of crystalline materials are highly dependent on intermolecular interaction and steric hinderance.Th...Based on three rationally designed pyrrole-appended o-carborane derivatives,we present that fluores-cence properties of crystalline materials are highly dependent on intermolecular interaction and steric hinderance.Though the three molecules are similar in structure,single crystals of the three compounds showed obvious difference in molecular stacking and fluorescence behavior.Systematic studies indicate that fluorescence quantum yields,thermo-response as well as mechano-response are highly dependent on intermolecular interaction and steric hindrance.In the three crystalline materials,the CB-NMe crys-tals with weaker intermolecular interaction and looser molecular packing showed superior fluorescence quantum yield and temperature sensitivity.Accordingly,surface temperature detection strip with favor-able reversibility is prepared by doping CB-NMe into the polymer.In addition,the CB-NMe aggregates can be used for monitoring bovine serum albumin(BSA)denaturation,as temperature response of the aggregates can be reversed when co-assembled with BSA.展开更多
The F-BAR domain containing proteins PACSINs are cytoplasmic phosphoproteins involved in various mem-brane deformations,such as actin reorganization,vesicle transport and microtubule movement.Our previous study shows ...The F-BAR domain containing proteins PACSINs are cytoplasmic phosphoproteins involved in various mem-brane deformations,such as actin reorganization,vesicle transport and microtubule movement.Our previous study shows that all PACSINs are composed of crescent shaped dimers with two wedge loops,and the wedge loop-mediated lateral interaction between neighboring dimers is important for protein packing and tubulation activity.Here,from the crystal packing of PACSIN 2,we observed a tight tip-to-tip interaction,in addition to the wedge loop-mediated lateral interaction.With this tip-to-tip interaction,the whole packing of PACSIN 2 shows a spiral-like assem-bly with a central hole from the top view.Elimination of this tip-to-tip connection inhibited the tubulation function of PACSIN 2,indicating that tip-to-tip interaction plays an important role in membrane deformation activity.Together with our previous study,we proposed a packing model for the assembly of PACSIN 2 on membrane,where the pro-teins are connected by tip-to-tip and wedge loop-mediated lateral interactions on the surface of membrane to gener-ate various diameter tubules.展开更多
The form-B monodinic insulin crystal was obtained from the sodium citrate buffer with 1% zinc chloride, keeping phenolic content between 0.76% and 1.25%. Its space group is P21, cell constants are: a = 4.924nm, b=6.09...The form-B monodinic insulin crystal was obtained from the sodium citrate buffer with 1% zinc chloride, keeping phenolic content between 0.76% and 1.25%. Its space group is P21, cell constants are: a = 4.924nm, b=6.094nm, c=4.818nm, β=95.8°. There are 6 insulin molecules which form a hexamer. The initial phase was obtained by using rotation function program of X-PLOR program package and molecular packing program of our laboratory. The molecular model was chosen from 4 zinc bovine insulin hexamer. After the preliminary refinement by using the rnacromolecular rigid body refinement technique, the molecular model was further refined and adjusted by using the energy-minimizing stereochemically restrained least-squared refinement on the difference Fourier maps. The finial R-factor is 214% at 0.3nm resolution, the r.m.s. deviations from standard bond length and bond angle are 0.0022nm and 4.7°, respectively.展开更多
文摘A monodispersed latex from styrene(St), methyl methacrylate(MMA) and acrylic acid(AA) was synthesized with the soap free emulsion polymerization, and the formation of colloidal crystal by evaporating the water of the latex was investigated. It has been confirmed that there exist two array manners, i.e., hexagonal and square array, and two packing modes, i.e., hexagonal packing and face-centered cubic packing in the forming process of colloidal crystals. The square array originated from the dislocation of the particle in the hexagonal array, the area of it depends on the temperature in the forming process. At a lower temperature such as at 0 ℃, relatively large areas of square array were observed in the formed colloidal crystal.
基金supported by the National Natural Science Foundation of China (21788102, 22275055, 22025503, 22220102004, 21875064, and 21790361)Shanghai Science and Technology Commission Basic Project Shanghai Natural Science Foundation (21ZR1417600)+5 种基金Shanghai Municipal Science and Technology Major Project (2018SHZDZX03)the Programme of Introducing Talents of Discipline to Universities (B16017)Shanghai Science and Technology Committee (17520750100)Science and Technology Commission of Shanghai Municipality (21JC1401700)the Fundamental Research Funds for the Central Universitiesthe support of Research Center of Analysis and Test of East China University of Science and Technology for the help on the characterization。
文摘Simultaneously achieving room-temperature phosphorescence(RTP) and multiple-stimuli responsiveness in a single-component system is of significance but remains challenging. Crystallization has been recognized to be a workable strategy to fulfill the above task. However, how the molecular packing mode affects the intersystem crossing and RTP lifetime concurrently remains unclear so far. Herein, four economic small-molecular compounds, analogues of the famous drug raloxifene(RALO), are facilely synthesized and further explored as neat single-component and stimuli-responsive RTP emitters via crystallization engineering. Thanks to their simple structures and high ease to crystallize, these raloxifene analogues function as models to clarify the important role of molecular packing in the RTP and stimuliresponsiveness properties. Thorough combination of the single-crystal structure analysis and theoretical calculations clearly manifests that the tight antiparallel molecular packing mode is the key point to their RTP behaviors. Interestingly, harnessing the controllable and reversible phase transitions of the two polymorphs of RALO-OAc driven by mechanical force, solvent vapor, and heat, a single-component multilevel stimuli-responsive platform with tunable emission color is established and further exploited for optical information encryption. This work would shed light on the rational design of multi-stimuli responsive RTP systems based on single-component organics.
基金supported by the National Natural Science Foundation of China(22201042 and 22371047)the Natural Science Foundation of Fujian Province(2022J05118,2022J01538 and 2023J01425)+1 种基金the Collaborative Innovation Platform Project of Fu-Xia-Quan National Independent Innovation Demonstration Zone(2022-P-021)Fuzhou Science and Technology(2022-P-001)。
基金supported by the Higher Education Commision(HEC),Govt.of Pakistan
文摘One-pot three component reaction was used to synthesize 1,4,5-trisubstituted 1,2,3-triazole(A) from the corresponding acid chloride, benzyl azide and 1-copper(I) phenylethyne. The molecular structure was determined by single-crystal X-ray analysis. The compound crystallizes in the orthorhombic space group Pbca, a = 14.9815(14), b = 9.6496(10), c = 25.528(2) A, Z = 8. Furthermore, crystal packing demonstrated a molecular wall-like structure based on supramolecular chains of A, stabilized by CH···O, CH···Br, N···C and CH···π interactions. Molecular geometry in the ground state has been determined by density functional theory(DFT) by B3LYP/6-311G* basis set and compared with the experimental data. The computed vibrational frequencies are compared with the experimental FT-IR data and frontier molecular orbital analyses were performed at the same level of theory. Theoretical parameters are in good agreement with the corresponding X-ray diffraction values.
基金Financial support from the National Natural Science Foundation of China(grant nos.22071258,21871280,21861132004,and 22088102)the Ministry of Science and Technology of China(grant no.2017YFA0206903)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(grant no.XDB17000000)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(grant no.QYZDY-SSWJSC029)the K.C.Wong Education Foundation is gratefully acknowledged.
文摘Quantitative oxygen detection is of great importance in biological fields,complex environments,and chemical process engineering.Due to the high sensitivity and rapid response of long-lived phosphorescence to oxygen,pure organic room-temperature phosphorescence(RTP)for oxygen detection has recently attracted considerable interest.However,to simultaneously achieve ultralong phosphorescence at room temperature and quantitative oxygen detection from pure organic crystals is difficult.Tight packing to restrict nonradiative decay is not apt to allow oxygen diffusion for sensing.Reported herein is an exceptional example,that is,a crystal of simple carbazole molecules that bridges with an ethoxysilane(DCzC2OSi)and is capable of oxygen sensing with remarkable sensitivity.Photophysical studies and single-crystal structure analysis reveal that DCzC2OSi crystals display ultralong RTP and suitable oxygen diffusion channels from its butterfly-like tetrahedron geometry.Further comparisons with the crystals of CzC2OH and DCzSi verify the important roles of silicon and ethoxy groups of DCzC2OSi for both enhanced phosphorescence lifetime and oxygen sensitivity.When the crystals of DCzC2OSi were doped into polymer,the lifetime-based oxygen sensor exhibited high KSV(5.308 kPa^(−1))with full reversibility,which is attractive for the development of practical oxygen sensors from pure organic crystals.
基金Supported by the National High Technology Research and Development Program of China (863 Program, No. 2009AA03Z217)the National Natural Science Foundation of China (No. 90922028)+1 种基金the Young Talent Program of Fujian Province (No. 2007F3060)the Fund of Fujian Provincial Key Laboratory of Nanomaterials (No. NM10-5)
文摘A new one-dimensional mixed-valence Cu（Ⅰ）/Cu（Ⅱ） complex [Cu（bipy）（Me2dtc）CuI2]n 1 （bipy = 2,2′-bipyridine and Me2dtc = N,N-dimethyldithiocarbamate） has been synthesized under solution condition, and characterized by elemental analysis, IR spectrum, single-crystal X-ray diffraction and magnetic property. The crystal belongs to the tetragonal system, space group P4122 with a = b = 11.6504（16）, c = 13.466（3） A, V = 1827.8（5） A^3, Z = 4, Dc = 2.389 g/cm^3, Mr = 657.27, λ（MoKa） = 0.71073 , μ = 5.931 mm·1, F（000） = 1236, the final R = 0.0483 and wR = 0.1245. A total of 2102 unique reflections were collected, of which 2009 with I 〉 2σ（I） were observed. 1 consists of polymeric [Cu^II2]nn^- anions and [Cu^II（bipy）（Me2dtc）]^＋ cations. It is interesting that the cations of 1 interact through π-π stacking interactions after rotating 90° to form one-dimensional chains parallel to the anion chains. The magnetic study indicates antiferromagnetic behavior for this complex.
基金supported by the National Natural Science Foundation of China (Nos. 50572030 and 50372022)the Research Fund of Huaqiao University (No. 06BS216)the Young Talent Program of Fujian Province (No. 2007F3060)
文摘A new mononuclear Cu（Ⅱ） dithiocarbamate complex CuI（prdtc）（phen） 1 （prdtc = N-pyrrolidinyldithiocarbamate, phen = 1,10-phenanthroline） was synthesized and characterized by elemental analysis, IR spectrum, and single-crystal X-ray diffraction. The crystal belongs to the monoclinic system, space group P21/c with a = 8.7110（9）, b = 14.7143（14）, c = 14.8507（15） A, β = 109.721（6）°, V = 1791.9（3） A3, Z = 4, Dc = 1.916 g/cm3, CI7H16CulN3S2, Mr = 516.89, λ（MoKa） = 0.71073A,μ = 3.178 mm^-1, F（000） = 1012, the final R = 0.0369 and wR = 0.0987. A total of 4082 unique reflections were collected, of which 2916 with I 〉 2σ（I） were observed. The Cu（Ⅱ） atom is five-coordinated in a distorted square-pyramidal geometry by one I atom in the apical position, two S atoms from a prdtc ligand and two N atoms from a phen ligand in the basal plane. There exist face-to-face aromatic π-π stacking interactions between adjacent phen ligands stabilizing the structure and making the complex assemble into a 1D structure along the a axis. It can be concluded that the difference of the dtc flexibility and reaction conditions result in the structural difference between complex 1 and CuI（dmdtc）（phen） （dmdtc = N, N-dimethyldithiocarbamate）.
基金supported by the Natural Science Foundation of Shandong Province (ZR2011EMQ007)the Doctoral Foundation of Jinan University (XBS1048)
文摘Two new organic crystals of 2,8-bisthienyldibenzothiophene（BTDT） and 2,8-bis-dithienyldibenzothiophene（BDTDT） compounds were successfully obtained.The change of end-capped group from thiophene to dithiophene causes big differences in molecular packing and carrier-transport property.The adjacent molecules of compound BTDT adopt face-to-face π stacking and exhibit two-dimensional interchain interactions.On the contrary,BDTDT molecules are arranged in an edge-to-face motif and show mainly one-dimensional interacting character.The packing mode exerts dramatic effect on the carrier-transport property.The crystal of BTDT belongs to the orthorhombic system,space group P21212 with a = 20.1427（11）,b = 4.6016（3）,c = 8.6340（5） ,V = 800.27（8） 3,Z = 2,Dc = 1.446 g/cm3,F（000） = 360,S = 1.019,the final R = 0.0491 and wR = 0.0960 for 1605 reflections with I 2σ（I）.The crystal of BDTDT belongs to the orthorhombic system,space group P212121 with a = 7.2636（15）,b = 25.359（5）,c = 25.359 ？,V = 4670.9（14） ？3,Z = 8,Dc = 1.458 g/cm3,F（000） = 2112,S = 0.880,the final R = 0.0597 and wR = 0.1318 for 8047 reflections with I 2σ（I）.
基金funding from the Natural Science Foundation of China (Nos. 22072084, 21820102005)111 Project (No. B14041)+1 种基金the Fundamental Research Funds for the Central Universities (Nos. GK202103048, GK202001005, 2020CSLY008)the Innovation Capability Support Program of Shaanxi (No. 2021TD-18)
文摘Based on three rationally designed pyrrole-appended o-carborane derivatives,we present that fluores-cence properties of crystalline materials are highly dependent on intermolecular interaction and steric hinderance.Though the three molecules are similar in structure,single crystals of the three compounds showed obvious difference in molecular stacking and fluorescence behavior.Systematic studies indicate that fluorescence quantum yields,thermo-response as well as mechano-response are highly dependent on intermolecular interaction and steric hindrance.In the three crystalline materials,the CB-NMe crys-tals with weaker intermolecular interaction and looser molecular packing showed superior fluorescence quantum yield and temperature sensitivity.Accordingly,surface temperature detection strip with favor-able reversibility is prepared by doping CB-NMe into the polymer.In addition,the CB-NMe aggregates can be used for monitoring bovine serum albumin(BSA)denaturation,as temperature response of the aggregates can be reversed when co-assembled with BSA.
基金the National High Technology and Develop-ment Program of China(973 Programs)(No.2010CB911800)the National Natural Science Foundation of China(Grant No.30930020).
文摘The F-BAR domain containing proteins PACSINs are cytoplasmic phosphoproteins involved in various mem-brane deformations,such as actin reorganization,vesicle transport and microtubule movement.Our previous study shows that all PACSINs are composed of crescent shaped dimers with two wedge loops,and the wedge loop-mediated lateral interaction between neighboring dimers is important for protein packing and tubulation activity.Here,from the crystal packing of PACSIN 2,we observed a tight tip-to-tip interaction,in addition to the wedge loop-mediated lateral interaction.With this tip-to-tip interaction,the whole packing of PACSIN 2 shows a spiral-like assem-bly with a central hole from the top view.Elimination of this tip-to-tip connection inhibited the tubulation function of PACSIN 2,indicating that tip-to-tip interaction plays an important role in membrane deformation activity.Together with our previous study,we proposed a packing model for the assembly of PACSIN 2 on membrane,where the pro-teins are connected by tip-to-tip and wedge loop-mediated lateral interactions on the surface of membrane to gener-ate various diameter tubules.
基金Project supported by the Chinese Academy of Sciences.
文摘The form-B monodinic insulin crystal was obtained from the sodium citrate buffer with 1% zinc chloride, keeping phenolic content between 0.76% and 1.25%. Its space group is P21, cell constants are: a = 4.924nm, b=6.094nm, c=4.818nm, β=95.8°. There are 6 insulin molecules which form a hexamer. The initial phase was obtained by using rotation function program of X-PLOR program package and molecular packing program of our laboratory. The molecular model was chosen from 4 zinc bovine insulin hexamer. After the preliminary refinement by using the rnacromolecular rigid body refinement technique, the molecular model was further refined and adjusted by using the energy-minimizing stereochemically restrained least-squared refinement on the difference Fourier maps. The finial R-factor is 214% at 0.3nm resolution, the r.m.s. deviations from standard bond length and bond angle are 0.0022nm and 4.7°, respectively.
