Chemistry of trichosanthin: VII. The chemical cleavage of the tryptophanyl peptide bond in trichosanthin

The single tryptophan residue of trichosanthin was cleaved by the use of BNPS-skatole reaction with STIG2 peptide fregment which was obtained from the tryptic digestion of N-succinyl trichosanthin. After separation, the N-terminal sequence of tryptophanyl C-side peptide was determined by use of manual DABITC-PITC double coupling sequencing method as follows: -Leu-Ala-Leu-Ser-Lys-Gln-Ile-Gln-Ile-Ala-.     

桥基取代2,7’-(乙烯基)-二-8-羟基喹啉类化合物的密度泛函理论研究

在B3LYP/6-31G(d)水平上对2,7′-(乙烯基)-二-8-羟基喹啉(2,7′-Ethq_2)及其6种桥基取代物的几何结构进行了全优化,探讨了取代基对分子的结构、电荷转移、前线分子轨道能级、能隙等方面的影响.采用含时的密度泛函理论(TD-DFT)研究各分子的气相及液相中的电子光谱,分析光谱的变化规律.结果表明,取代基的电子效应和立体效应对取代物的电子结构和电子光谱有重要影响,取代基重新调整了2,7′-Ethq_2的原子电荷布居,改变了前线分子轨道能隙,导致吸收光谱发生变化.氨基和氰基对2,7′-Ethq_2影响较为显著,吸收波长红移较大.此外溶剂的极性对其电子光谱也有影响,随溶剂极性的增大,硝基取代物的最大吸收波长发生明显的红移,其它取代物的最大吸收波长均发生较小的蓝移.     

二维层状镉配合物[CdCl_2(obbm)]的合成、晶体结构及荧光性质(英文)

<正>The self-assembly of metal-organic frameworks (MOFs) have attracted much attention, due to their intriguing structural topologies and wide potentialapplications as functional materials for heterogeneous     

Structure modulation of metal–organic frameworks via reaction pH: Self-assembly of a new carboxylate containing ligand N-(3-carboxyphenyl)iminodiacetic acid with cadmium(II) and cobalt(II) salts

Self-assembly of a new carboxylate containing ligand, N-(3-carboxyphenyl)iminodiacetic acid (H₃L), with Cd(II) and Co(II) salts under different reaction pH results in the formation of four new coordination polymers, namely [Cd(HL)(H₂O)] (1), [Co(HL)(H₂O)] (2), [Cd(HL)(H₂O)₄] (3) and [Cd₃(L)₂(H₂O)₉] · 7H₂O (4). Single crystal X-ray diffraction analysis indicates that 1 and 2 are isomorphous and isostructural with a 2D wave-like network structure, while 3 has a 1D zigzag chain structure. The complexes 1–3 were obtained at low pH (<7) which makes the ligands only partly deprotonated. However, complex 4, obtained at pH 7 with all the carboxylate groups deprotonated, exhibits a 2D network structure. The results suggest that the reaction pH is one of the key factors in the formation of the coordination architectures. In addition, the photoluminescence properties of the free ligand (H₃L) and complexes 1, 3 and 4 were studied in the solid state at room temperature. Moreover, the magnetic property of complex 2 was investigated.     

三种新型铜配合物的合成、结构及理论计算

合成了一个柔性配体1,3-二(N-咪唑基甲基)苯(mbix)(1), 并将其与不同Cu盐组装, 得到3个新配合物[Cu(mbix)2(H2O)]·2NO3·CH3OH(2), [Cu(mbix)(N3)(OAc)]·CH3OH(3)和[Cu(mbix)2]·SiF6·2CH3OH(4), 并对其进行了元素分析、红外光谱及X 射线单晶结构分析表征. 配合物2拥有二维二重贯穿结构, 配合物3中两个铜离子通过两个叠氮酸根桥连成双核铜, 它再通过配体连接形成一维绞链状结构, 而配合物4通过配体桥联成一维无限链状结构. 结果显示, 平衡阴离子在配合物的组装过程中起着非常重要的作用. 此外还对配体及3个配合物中配体的构象进行了理论计算.     

具有新颖拓扑结构的吡啶基羧酸配体钇配合物的合成，晶体结构和拓扑学分析

利用水热合成制备了一个新的吡啶基多羧酸钇配合物YL(HL).2H2O(1)(H2L=5-((吡啶基-3-亚甲基)氨基)间苯二甲酸)。利用元素分析及X-射线单晶衍射对其进行了表征。结构分析结果表明标题化合物1属于三斜晶系,P1空间群,晶胞参数为a=1.015 35(11)nm,b=1.083 33(12)nm,c=1.287 40(14)nm,α=70.9430(10)°,β=127.689(3)°,γ=84.0680(10)°,晶胞体积V=1.317 0(2)nm3,Z=2,Dc=1.680 g.cm-3,F(000)=680,μ=2.284 cm-1,R=0.056 2,wR=0.1600。在化合物1中,每个Y的配位环境为八配位的反四棱柱配位构型。该配合物的二维结构是少见的(42.6)(42.67.8)层状拓扑。我们对配合物1的粉末衍射数据和热重分析也进行的讨论。     

配位聚合物[Cd2(BDC)2(obix)2]·H2O的合成、晶体结构和荧光性质

用水热合成方法得到1个新的配位聚合物[Cd2(BDC)2(obix)2]·H2O(H2BDC=对苯二甲酸,obix=1,2-(二亚甲基)二咪唑).配合物晶体属三斜晶系,P1空间群.晶体结构表明:镉原子与3个对苯二甲酸上的5个氧原子,2个1,2-(二亚甲基)二咪唑中的2个氮原子配位形成扭曲的五角双锥配位构型.2个Cd(Ⅱ)原子通过两个羧基桥联形成一个双核Cd2单元,再通过配体连接成二维层状结构,层与层之间通过C-H…O氢键和弱的π-π相互作用形成三维超分子结构.室温下配合物具有较强的荧光发射光谱.     

以芳香羧酸及双咪唑基化合物为配体的钴配合物的合成和晶体结构

以硝酸钴、4,4’-（六氟异丙基）二（苯甲酸）（H₂FBA）和1,2-二咪唑基二甲苯（OBIX）或4,4’-二咪唑基二甲联苯（BIMB）为原料,在水热条件下得到2个结构不同的配位聚合物[Co（OBIX）（FBA）]_n（1）和[Co₂（BIMB）₂（FBA）₂]_n（2）。对它们进行了元素分析、红外光谱分析,并利用X-射线衍射测定了它们的单晶结构。配合物1中2个钴离子通过2个OBIX配体桥连成一个24元大环,它再通过FBA配体连接成一维管状结构,而配合物2中钴离子通过两种配体连接成一维左右两种螺旋结构,2种螺旋结构通过交替互锁形成二维层状结构。结果说明了辅助配体在配合物组装过程中起着非常重要的作用。     

以对苯二氧基二乙酸和咪唑基化合物为配体的镍、镉配合物的合成和晶体结构

以对苯二氧基二乙酸(H₂BDOA)和4,4'-二咪唑基二苯醚(BIDPE)为原料,分别与氯化镍、氯化镉在水热条件下反应,得到2个结构不同的配位聚合物[Ni(BDOA)(BIDPE)(H₂O)]_n(1)和[Cd(BDOA)_0.5(BIDPE)Cl]_n(2)。对它们进行了元素分析、红外光谱分析,并利用X-射线衍射测定了它们的单晶结构。配合物1属于三斜晶系,P1空间群,a=0.93497(8)nm,b=1.03231(9)nm,c=1.35291(12)nm,α=96.3980(10)°,β=90.7290(10)°,γ=102.0270(10)°,V=1.26831(19)nm³,Z=2,M_w=603.22,D_c=1.580g·cm^-3,μ=0.827,F(000)=624,R₁=0.0395,wR₂=0.0895(I>2σ(I))。配合物2也属于三斜晶系,P1空间群,a=1.01751(7)nm,b=1.04299(7)nm,c=1.17338(8)nm,α=68.7230(10)°,β=71.8260(10)°,γ=76.0910(10)°,V=1.09105(13)nm³,Z=2,M_w=562.26,D_c=1.711g·cm^-3,μ=1.163,F(000)=562,R₁=0.0210,wR₂=0.0537(I>2σ(I))。配合物1中镍离子通过2种配体桥联成二维波浪形层状结构,而配合物2中镉离子通过2个Cl离子连接成一个双核Cd₂单元,双核单元再通过2种配体连接成一维链状结构。结果说明了金属离子在配合物组装过程中起着非常重要的作用。此外,研究了它们的荧光性质。     

Synthesis,Crystal Structure,Electronic Absorption and Magnetic Properties of a Novel Anion-Radical Salt Based on 7,7,8,8-Tetracyanoquinodimethane

Abstract  

A novel anion-radical salt, (AP)(TCNQ)·H₂O (1), where AP = 4-amino-1-butylpyridin-1-ium and TCNQ = 7,7,8,8-tetracyanoquinodimethane, has been synthesized. X-ray single crystal structural analyses show that the TCNQ anions and AP cations form a well-separated stacking column. The TCNQ anions are uniformly spaced to give a one-dimensional (1-D) chain structure through π···π interactions, which is rarely observed in TCNQ anion-radical system. It is noteworthy that compound 1 shows a peculiar magnetic transition from paramagnetism in the high-temperature (HT) phase to spin gap in low-temperature (LT) phase.