以2-甲基-丙烯酸,4-(吡啶-4-偶氮)-苯酯为配体的四个配位化合物的合成、晶体结构和紫外吸收

4个单核配位化合物,[Zn(Maape)2(H2O)2(NO3)2] (1, 单核), [Cu(Maape)2(H2O)2(NO3)2] (2, 单核), [Zn(Maape)2Cl2] (3, 单核), [Zn(Maape)(H2O)4SO4] (4, 单核),都是用过渡金属盐和配体2-甲基-丙烯酸,4-(吡啶-4-偶氮)-苯酯合成的.四个化合物由单晶X-射线衍射和结构分析表明都是单核化合物.另外,还通过红外和元素分析对其进行表征.配位化合物的结构不仅受配位金属离子的影响还受不同配位阴离子的影响.化合物1和2的结构都是由一个金属离子中心、2个配位硝酸根离子和2个配体分子组成的单核配合物.化合物3的单核结构中包含一个Zn(II)、2个氯离子和2个配体分子.而化合物4的不对称单元[Zn(Maape)(H2O)4SO4]中Zn(II)中心位于二重对称轴上.在本文中,配体和4个化合物都在323 nm处有最高紫外吸收峰.     

配合物2[NiL2(H2O)2]·DMF的合成、晶体结构与荧光性质的研究

以喹啉-2-甲酸与醋酸镍为原料,采用水热法合成配合物2[NiL₂(H₂O)₂]·DMF(L=喹啉-2-甲酸根离子,DMF=N,N-二甲基甲酰胺),并通过X-射线单晶衍射、X-射线粉末衍射、元素分析、红外光谱、热重分析、荧光光谱对其进行结构解析和性质表征.晶体结构解析表明:标题配合物晶体属于正交晶系,空间群为Pna21;其晶胞参数是:a=2.06753(6)nm,b=0.82571(3)nm,c=2.34776(7)nm,V=4.0081(2)nm³,Z=4,Mr=951.210,Dc=1.576 g/cm³.标题配合物为单核配合物,配位单元之间通过分子间氢键和π-π堆积作用,把配合物扩展为三维超分子结构.荧光光谱分析表明配体和标题配合物均有良好的荧光性,且配合物荧光性优于配体.     

锰(Ⅱ)与5-[(蒽-9-亚甲基)-氨基]-间苯二甲酸的超分子配位聚合物的合成、表征及性能研究

以桥联配体5-[(蒽-9-亚甲基)-氨基]-间苯二甲酸和Mn(CH3COO)2·4H2O 为原料,通过溶剂热法成功合成了一个新型三维超分子结构的配位聚合物{[Mn2(H2O)4(CH3OH)(C2H5OH)(L)2]·(CH3OH)2·H2O}n(H2L=5-[(蒽-9-亚甲基)-氨基]-间苯二甲酸),并通过红外光谱、元素分析、X射线粉末衍射、单晶 X 射线衍射和热重分析,对配位聚合物的单晶结构进行了表征.该配位聚合物属于三斜晶系,空间群P-1,晶胞参数:a=9.6850(19) nm,b=14.278(3) nm,c=17.666(4) nm,α=87.15(3)°,β=89.99(3)°,γ=83.96(3)°,V=2426.3(8) nm3,Z=2.该晶体结构为一维配位链,通过链与链之间的π…π相互作用和氢键形成了三维超分子结构.此外,在室温条件下,固态荧光测试表明配体及其配位聚合物分别在456 nm (λex=417 nm)和506 nm (λex=402 nm)具有较强的荧光.     

以1,2,5-噻二唑-3,4-二酸为配体的碱土金属配合物的合成、晶体结构及配位模式

以1,2,5-噻二唑-3,4-二酸为单一配体与第二主族碱土金属离子通过水热法合成了三个配合物,对其进行了元素分析及单晶衍射结构解析,并对H2tdzdc配体的配位能力、配位模式等特性作了初步研究.结果表明:单核配合物1,[Mg(tdzdc)(H2O)4]属于三斜晶系,空间群为P1;配位聚合物2,[Ca(tdzdc)(H2O)2]n,具有二维层状结构,属于单斜晶系,空间群为C2/c;配位聚合物3,[Sr(tdzdc)(H2O)3]n,具有二维层状结构,属于三斜晶系,空间群为P1.通过研究发现,当使用ⅡB主族的碱土金属与1,2,5-噻二唑-3,4-二酸根进行配位时,随着金属离子半径的增加和电子层数的增多,金属离子的配位数增多,得到的Mg、Ca、Sr的配合物结构愈加复杂,即从单核配合物到配位聚合物.     

1,2,3-三唑羧酸铜(Ⅱ)配合物的合成、晶体结构与性质

通过水热的方法制备了两个新的1,2,3-三唑羧酸铜配合物:[Cu(L1)2· 2H2O](1)和[Cu(L2)2]n(2)(HL1=4-苯基-1,2,3-三唑-1-乙酸,HL2=4-苯基-1,2,3-三唑-2-乙酸),并利用红外光谱、质谱(MS)、核磁共振氢谱(1 H NMR)、元素分析、X-射线单晶衍射、X-射线粉末衍射和热重分析进行了表征.晶体结构表明:配合物1中,每一个单核分子通过分子间氢键作用形成二维层状结构.配合物2中,铜原子通过与羧基上的氧原子采用顺-反双齿桥联,形成了二维的网状结构,进一步通过每层网状结构间的π-π堆积作用形成三维超分子结构.磁性测试结果表明配合物2在低温下表现为铁磁性相互作用.     

之字链配合物Cu(phth)2(H2O)2的合成、表征及晶体结构

用Cu(NO3)2·3H2O和phth(邻苯二甲酸)混合反应得到了配合物Cu(phth)2(H2O)2(1).通过元素分析、红外光谱对配合物进行了表征,用X射线单晶衍射仪测定了配合物的晶体结构.配合物为单斜晶系,P2(1)/c空间群.晶胞参数a=0.83895(17)nm,b=1.4441(3)nm,c=0.70992(14)nm,β=112.14(3)°,V=0.7967(3)nm3,Z=2,Dc=1.792 g/cm3,F(000)=438.0,S=1.100,R1=0.0376,wR2=0.0998.铜原子为四配位,呈畸变正方形构型,通过邻苯二甲酸根的π-π堆积作用形成了一维之字型链,相邻的链之间靠氢键和π-π堆积作用形成三维分子结构.     

一维链状镉有机膦酸配合物的合成、结构和荧光性质研究

基于有机膦酸配体(5-pncH3=(5-phosphono-1-naphthalenecarboxylic acid)和过渡金属镉盐水热法自组装得到一维锯齿链状配合物Cd0.5(5-pncH2)(H2O)1.5(1).采用X-射线单晶衍射、元素分析、红外光谱、X-射线单粉末衍射、热重分析对配合物进行表征.晶体结构分析表明:该配合物结晶于正交晶系,Pbcm空间群,a=0.69343(2)nm,b=0.887153(3)nm,c=4.18876(15)nm.配合物1具有一维链状结构,其中相邻的CdI离子通过配位水分子桥联成一维锯齿链.链内存在相邻的萘环棱面堆积的C-H?π作用,链间相邻的链通过有机膦酸配体上的羧基双重氢键形成二维层状结构,层与层之间通过范德华作用力连接成三维超分子网络骨架.研究了配合物的热稳定性和光致发光性质.     

2-磺基对苯二甲酸与多吡啶配体的锰(Ⅱ)配合物的晶体结构和磁学性质

利用2-磺基对苯二甲酸钠(2-NaH2stp)、2,4,6-三(2-吡啶)-5-嗪(tpt)和水合醋酸锰在溶剂热条件下合成了一种二维的新型配合物[Mn3 (stp)2 (tpt)3(H2O)2](H2O)2(1).结构分析表明,该配合物中有两个晶体学独立的锰离子,Mn1与6个氧原子配位,Mn2与3个氧原子和3个氮原子配位,均处于八面体构型.Mn2离子通过stp配体链接成双螺旋一维链,而Mn1离子将一维链进一步链接成二维层结构,层间通过晶格水分子的氢键和tpt分子间的π…π堆积作用堆垛成三维超分子结构.配合物1的磁学性质研究表明,金属离子Mn(Ⅱ)之间存在弱的反铁磁相互作用.     

苯并[d]咪唑基Ni(Ⅱ)配合物的合成、晶体结构与荧光性质研究

以3-(4-羧苯基)-7-甲基-2-丙基-3H-苯并[d]咪唑-5-羧酸和六水合氯化镍为原料,采用混合溶剂加热回流方法合成出了一例具有三维超分子结构的镍配合物,并通过X射线单晶衍射、元素分析、红外光谱、紫外-可见光光谱和荧光光谱表征方法对其进行了结构解析和性质表征。X-射线单晶衍射结果表明,配合物属于三斜晶系,P1空间群;其晶胞参数为a=0.778 5(16) nm,b=1.126 6(2) nm,c=1.175 6(2) nm, α=113.63(3)°,β=93.24(3)°,γ=101.00(3)°,V=0.917 1(3) nm³。标题配合物为单核配合物,由4个配体阴离子连接中心Ni(II)离子形成了一维环形链,并进一步通过氢键和π-π堆积作用形成了三维超分子结构。荧光光谱分析结果表明配体和标题配合物均具有良好的荧光性质,且配合物的荧光性质优于配体。     

樟脑酸构筑的铜、钴配合物的合成、晶体结构及电化学性质

分别采用普通溶液法和溶剂热法合成了两个以樟脑酸(D-H2Cam)为主配体的配合物.X射线单晶衍射分析结果表明:配合物[Cu(D-HCam)2(phen)]·2H2O (1)为单核配合物,四方晶系,P41212空间群,中心铜离子处于变形的四边形的配位环境;配合物{[Co(Hcam)2(4,4'-bipy)(H2O)2]·0.4(H2O)2·3.2H2O}n(2)为一维分子链,正交晶系,C2221空间群,有六个原子在钴原子周围形成一个稍变形的八面体配位环境.同时对两个配合物的热稳定性和电化学性质进行了研究.     

Synthesis and Structure Determination of 1, 4, 7, 11, 14, 17, 21, 24, 27-Nonaoxatriacontan-8, 10, 18, 20, 28, 30-Esaone

The title compound crystallizes in the trigonal space group R-3, with unit-cell parameters: a = 23.261(4), c = 9.537(2) Å; λ(MoKα) = 0.71073 Å, V = 4469(2) Å³, and Z = 6. The structure has been solved by direct methods using X-ray diffraction techniques. The final reliability index for the computed structure is 0.0826 for 929 observed reflections and 121 refined parameters. Crown ether adopts an almost circular shape and macrocycles are piled up in a columnar arrangement forming tubular nanochannels. The channels are filled with guest CDCl₃ molecules, characterised by rotational disorder.     

Apparent entropy,residual entropy,causality, metastability,constraints, and the glass transition

A thermodynamic framework for the investigation of ‘residual entropy’ and related phenomena is developed, expanding and clarifying the work of Kivelson and Reiss and the important work of several other investigators. The main difficulties encountered in the development of such a framework are the need to deal with constrained equilibrium as well as to include irreversible processes in the overall study. These challenges are met by using the device of auxiliary constraints and the equivalent equilibrated states that they produce. The importance of a thermodynamic framework is tied to the fact that evolving molecular theories of residual entropy, which also impact the glass transition, no matter how sophisticated, invariably contain approximations whose effects are hard to assess. Thus a thermodynamic framework provides a vehicle within which the internal consistency of a theory can be tested. Phenomena that are treated in such a framework, along with others, are those mentioned in the title of this paper. The concept of residual entropy, its reality or unreality, is often considered to be an unimportant issue. The findings of this paper, besides emphasizing the unreality of residual entropy, show that the question of its existence is a significant one. Among other things, the fundamental principle of causality is involved and we should not be so cavalier as to dispense with it. Among other rigorous analysis we present an argument involving an ideal binary solution whose behavior as the limiting behavior of a real solution provides access, in principle, to experiment. The argument does make the generally accepted assumption that, at equilibrium at 0 K, pure crystals of the binary system’s components have zero entropy. It strongly suggests that residual entropy, in general, is an impression that stems from the inclusion of an irreversible step in an experimental thermodynamic cycle.     

Intermetallic Compounds KnMm (М = Ag,Au, As,Sb, Bi,Ge, Sn,Pb): Geometrical and Topological Analysis,Cluster Precursors,and Self-Assembly of Crystal Structures

Crystallography Reports - A geometrical and topological analysis and simulation of the self-assembly of the crystal structures of intermetallic compounds formed in the K–M (M = Ag, Au, As,...     

Intermetallic Compounds CsnMk (М = Na,K, Rb,Pt, Au,Hg, Te): Geometrical and Topological Analysis,Cluster Precursors,and Self-Assembly of Crystal Structures

Crystallography Reports - A geometrical and topological analysis has been performed, and self-assembly of the crystal structures of intermetallic compounds CsnMk (М = Na, K, Rb, Pt, Au, Hg,...     

D-β,β-dimethylcysteic acid,its preparation,structure, and spectroscopic properties

The X-ray crystal structure ofd-,-dimethylcysteic acid, C₅H₁₁NO₅S, has been determined. The compound is monoclinic, space groupP2₁₄ (No. 4), with cell dimensionsa=8.133(1),b=8.094(1),c=6.3138(7) Å,=96.36(1)° andZ=2. The structure was solved by Patterson and electron density difference methods and refined toR=0.025,R _w=0.022 for 1081 reflections. Bond lengths and angles do not differ from those in similar structures. The crystal is held together by intermolecular hydrogen bonds. The vibrational spectra have been recorded and assigned and the¹ H and¹³C NMR spectra were measured.     

Glass foams: formation, transport properties, and heat, mass, and radiation transfer

Energy efficiency, environmental impact, and quality of the final product in glass manufacturing depend, to a large extent, on foams formed on the surface of the molten glass and of the batch due to entrapment of gas bubbles generated by the batch fusion and refining chemical reactions during the melting process. Hence, understanding the mechanisms of foam formation as well as development of theoretical models for thermophysical and transport properties and heat, mass, and radiation transfer in glass foams are not only a problem of significant fundamental interest but also of tremendous practical impact. In this paper, the review of the current state-of-the-art in our understanding of glass foams is provided, including some of our recent results in modeling the dynamics of the foam growth and its steady-state thickness, prediction of gas diffusion through glass foams, and thermal radiative properties of glass foams. In addition, the new results on simulation of combined conduction and radiation heat transfer in glass foams and radiative transfer in primary (batch) foams are presented and discussed in some detail. The paper also presents practical means available for reducing foaming in glass melting and concludes with the discussion of unresolved problems and summary of the directions for the future work in the area.     

Crystal and molecular structure of dihydro-8b,8c-diphenyl-1H,3H,4H,5H,7H,8H,-2,6-dioxa-3a,4a,7a,8a-tetraazacyclopenta[def]fluorene-4,8-dithione

The title compound C₂₀H₁₈N₄O₂S₂ crystallizes in the monoclinic space group P2₁/n witha=8.4930(1) Å,b=11.4880(1) Å,c=20.0709(2) Å, =94.933(1)°,V=1951.01(3) ų,Z=4. The crystal structure has been solved by vector search methods and refined by fullmatrix least-squares toR=0.04 for 2888 reflections and 116 restraints. The title compound has a suitable geometry for synthesizing receptor molecules with a cleft for selective complexation.     

Intermetallic Compounds LikMn (M = Ag,Au, Pt,Pd, Ir,Rh): Geometrical and Topological Analysis,Tetrahedral Cluster Precursors,and Self-Assembly of Crystal Structures

Crystallography Reports - A combinatorial and topological analysis has been performed and self-assembly of the crystal structures of intermetallic compounds formed in the Li–M (M = Ag, Au,...