配合物Co(H2O)4(μ2-H2O)2K2(H2O)4(Hpht)4的合成与晶体结构

在水溶液中用硫酸钴与邻苯二甲酸氢钾反应得到了分子式为Co(H2O)4(μ2-H2O)2K2(H2O)4(Hpht)4的配合物,通过X-射线单晶衍射研究了其结构.该配合物的晶体属单斜晶系,空间群P21/c,晶胞参数a=10.430 7(2),b=6.857(3),c=29.577 5(5),β=97.987 0(10)°,V=2094.90(5)3,Z=2,Dc=1.550g/cm3,Mr=977.77,F(000)=1010,μ(MoKα)=0.702 mm-1,R1=0.0723,wR2=0.1875(I>2σ(I)).晶体分析表明钴与6个水分子的氧原子配位,其中两个氧原子作为桥联原子和两个K原子配位;K原子是五配位的,其他的配位原子来自两个水分子和两个Hpht,分子通过氢键构成沿ab面的层状结构.     

吡嗪-2-甲酸锌配合物的合成及其晶体结构

使用吡嗪-2-甲酸和高氯酸锌合成了单核配合物[Zn(pyr)2(H2O)2](Pry=吡嗪-2-甲酸根阴离子),并对所合成的配合物进行了X-射线衍射测定,获得了其晶体结构.该晶体属于单斜晶系,空间群为:P21/c,相关晶胞参数为:a=5.2789(17)A,b=11.097(4)A,c=10.318(3)A,β=99.350(4)°.该配合物中的锌原子被两个氮原子和四个氧原子所配位,形成了一个稍微畸变的配位八面体,其中两个配位氧原子来自于水分子而其它配位原子则由吡嗪-2-甲酸根配体提供.     

二维配位聚合物[Ni(C8H6NO4)2(H2O)2]n·2nH2O的合成和晶体结构

在N,N-二甲基甲酰胺／水混合溶剂中,5-氨基间苯二甲酸与六水氯化镍通过溶剂／水热反应得到了二维的配位聚合物单晶[Ni(C8H6NO4)2(H2O)2]n·2nH2O;添加水杨醛有助于得到较大的单晶.X-射线单晶衍射分析表明,标题配合物属于单斜晶系,C2／c空间群,晶胞参数为a=14.195(3)(A),b=11.150 (2)(A),c=12.578(3)(A),β=113.52 (3)°,V=1825.5 (6)(A)3,Z=4,Dc=1.787g.cm-3,μ=1.14 mm-1,F(000)=1016.在配合物中,Ni(Ⅱ)为六配位的八面体构型;5-氨基间苯二甲酸只有一个氨基氮原子和一个脱去质子的羧酸氧原子与Ni(Ⅱ)配位,其另一个羧酸保持质子化形式不参与配位.红外光谱分析进一步证实了配体的配位模式.     

配位聚合物Ni(2,6-DPC)2Ni(H2O)5·2H2O的水热合成与表征

在水溶剂中通过2,6-吡啶二羧酸和NiCl2·6H2O反应生成三维配位聚合物Ni(2,6-DPC)2 Ni(H2O)5·2H2O(DPC=2,6吡啶二羧酸)1.对其进行元素分析、红外光谱分析、热重量分析和单晶X射线衍射测定.该配合物属P2(1)/c.晶胞参数a=8.3261(17)A,b=27.227(5)A,c=9.6556(19)A,β=98.67(3)°,V=2163.9(7)(A)3,Z=7,F(000)=1248,R=0.0618,wR2=0.1721.该配位聚合物中镍配位有两种情况:Ni(1)与6个氧原子配位,有5个是与水分子中的氧配位另外一个是与Ni (2)相连的pdc2-的羧基氧.Ni(2)与全部来自pdc2-的四个羧基氧和两个氮原子配位.未配位的羧基氧和另一单元的配位水之间存在氢键,因此,这个结构集团相连接形成无限的一维链.此外,通过氢键的相互作用结构扩展到二维结构.最终,聚合物在氢键和π-π键作用下拓展为三维网状结构.     

二维网状冠醚配合物:[Na(B18-C-6)(H2O)]2 [Ni(mnt)2]的合成与晶体结构

研究了苯并18-冠-6与Na2[Ni(mnt)2](mnt=丁二腈烯二硫醇阴离子,[C2S2(CN)2]2-)的反应,得到配合物[Na(B18-C-6)(H2O)]2[Ni(mnt)2].通过红外光谱、元素分析及X-射线单晶结构衍射对配合物进行表征.结果表明该配合物为单斜晶系,空间群P21/n,晶体学数据a=1.015 4(2),b=1.209 7(3),c=2.101 1(5)nm,β=101.085(3)°,V=2.532(6)nm3,z=2,Dcalcd=1.371 g/cm3,F(OOO)=1 092,R1=O.040 8,wR2=O.088 3.配合物由两个[Na(B18-C-6)(H2O)]+配阳离子和一个[Ni(mnt)2]2-配阴离子组成,配阴离子[Ni(mnt)2]2-中的氮原子与[Na(B18-C-6)(H2O)]+的钠原子成键,与钠原子配位的H2O与冠醚氧原子通过氢键相互作用,形成了二维网状结构.     

新型超分子配合物{[Cu(Hhbd)(Nphe)]·H2O}·3H2O的合成、晶体结构与表征

采用羟基丁二酸铜与5-硝基邻菲咯啉反应合成了新型三维超分子配合物{[Cu(Hhbd)(Nphe)]·H2O}·3H2O(其中Hhbd=羟基丁二酸根,Nphe=5-硝基邻菲咯啉),通过元素分析、红外光谱、热分析和X射线单晶衍射等技术对其进行了表征.配合物属单斜晶系,空间群C2/c;晶胞参数a=1.7651(3)nm,b=1.9229(3)nm,c=1.2427(19)nm,β=99.50(3)°,V=4160.4(11)A3;Z=8;最终偏离因子R1=0.0573,wR2=0.1169.配合物中每个铜(Ⅱ)原子与来自5-硝基邻菲咯啉的两个氮原子、羟基丁二酸根的三个氧原子以及一个水分子的氧原子配位,形成畸变的八面体结构;紧邻单元通过邻菲罗啉环间的π-π堆积作用形成一维超分子链;链间籍羧基氧原子与配位水分子、未配位的羟基氧原子与羧基氧原子形成O-H…O氢键的连接拓展为三维超分子结构.     

糠醛水杨酰腙镍配合物的合成、表征与晶体结构

合成了以糠醛水杨酰腙为配体的一个镍配合物Ni(C12H9N2O3)2(C5H5N)2,进行红外光谱和紫外光谱分析,并测定晶体结构.该晶体为深红褐色,属三斜晶系,空间群为P1-,晶胞参数:a=1.02003(4)nm,b=1.11947(6)nm,c=1.48619(9)nm,α=105.960(2)°,β=93.819(2)°,γ=100.457(1)°.晶体结构分析表明,Ni2+具有畸变的八面体配位构型,配位原子分别来自两个二齿配体糠醛水杨酰腙的两个氧原子和两个氮原子以及两个配位吡啶的氮原子.     

二(N~3-水杨酰吡啶-2-羰基氨基腙基-κ~3N~1,N~2,O)合镍(Ⅱ)·二甲基甲酰胺的合成与晶体结构(英文)

配合物[Ni(spa)2](Hspa=N3-水杨酰吡啶-2-羰基氨基腙)用Hspa与Ni(Ac)2.4H2O反应制备.标题化合物的单晶X射线研究表明,Ni原子是位于两个三齿配体中的吡啶氮原子,氨基腙上的氮原子和甲氨酰基中的氧原子配位的畸变八面体形式中.该晶体属三斜晶系,P1空间群;a=1.063 58(3)nm,b=1.193 80(3)nm,c=1.26 354(3)nm,α=70.109 0(10)°,β=81.722 0(10)°,γ=87.476 0°,V=1.492 87(7)nm3,Z=2,Mr=642.32(C29H29N9O5Ni),Dc=1.429g.cm-3,μ=0.705 mm-1,F(000)=668,对于I>2σ(I)的4 487个反射点,R=0.030 8,Rw=0.080 4.在晶体结构中,存在两个羟基的O—H…N分子内氢键,此外两个N—H…O分子间氢键连接相邻的配合物形成一条平行于c轴的链,另一个N—H…O分子间氢键连接溶剂DMF分子.     

2个酰腙Schiff碱镍(Ⅱ)配合物的合成及其晶体结构研究

采用溶液合成法合成了2个酰腙Schiff碱的镍(Ⅱ)配合物[Ni(HOpbh)2].2H2O(1)(H2Opbh=2-羰基丙酸苯甲酰腙)和[Ni(HOpsh)(py)3].CH2Cl2(2)(H3Opsh=2-羰基丙酸水扬酰腙,py=吡啶).单晶X-射线结构分析表明,配合物1:晶体属四方晶系,I4122空间群,晶胞参数a=b=1.468 6(2)nm,,c=2.108 8(6)nm,V=4.548 1(16)nm3,Z=8,Dc=1.475 mg/m3,最终可靠因子R1=0.054 8,wR2=0.151 2.配合物2:晶体属单斜晶系,P21/c空间群,晶胞参数a=1.527 4(5)nm,b=1.170 5(4)nm,c=1.694 6(5)nm,β=113.364(6)°,V=2.781 2(15)nm3,Z=4,Dc=1.436 mg/m3,最终可靠因子R1=0.034 0,wR2=0.085 5.在配合物1中,每个镍(Ⅱ)离子由2个2-羰基丙酸苯甲酰腙负一价离子HOpbh-的4个氧原子和2个氮原子配位,形成畸变的八面体配位构型.配合物1分子间通过氢键的相互作用而形成1维链状结构.在配合物2中,每个镍(Ⅱ)离子由1个2-羰基丙酸水扬酰腙负二价离子HOpsh2-的2个氧原子和1个氮原子、3个吡啶分子中的氮原子配位,形成畸变的八面体配位构型.     

[Ni(C18H22N2O4)·2CH3OH]的合成和晶体结构

合成了配合物[Ni(C15H22N2O4)·2CH3OH],其结构通过元素分析和X-射线单晶衍射分析确定.中心原子Ni(Ⅱ)与两个氮原子和四个氧原子配位,形成扭曲的八面体结构.标题化合物(C20H28N2NiO6,Mr=45.15)属于,空间点群Pna2(1),晶体学参数a=10.0489(16)(A),b=21.020(3)(A),c=9.9769(16)(A),α=β=γ=90°,V=2107.4(6)(A)3,Z=4,Dc=1.422Mg·m-3,μ(MoKα)=0.959 mm-1,F(000)=952,and R1=0.025 8,wR2=0.062 8.     

金属有机框架衍生单原子纳米酶的合成、表征与生物应用研究进展

单原子催化剂（SACs）具有高原子利用效率以及高催化活性，在各种催化体系中均表现出优异的性能.其原子级别的活性位点与天然的金属蛋白酶类似，因此单原子纳米酶（SAzymes）的概念也应运而生.而金属有机框架（MOF）由于其具有高孔隙率的特点，可以作为合成SAzymes的前驱体.该文总结了使用MOF前体/模板构建SACs的合成策略，以及SAzymes的生物应用，提出了基于MOF衍生的SAzymes的发展挑战和前景.     

Nonlinear and quantum atom optics

Coherent matter waves in the form of Bose-Einstein condensates have led to the development of nonlinear and quantum atom optics - the de Broglie wave analogues of nonlinear and quantum optics with light. In nonlinear atom optics, four-wave mixing of matter waves and mixing of combinations of light and matter waves have been observed; such progress culminated in the demonstration of phase-coherent matter-wave amplification. Solitons represent another active area in nonlinear atom optics: these non-dispersing propagating modes of the equation that governs Bose-Einstein condensates have been created experimentally, and observed subsequently to break up into vortices. Quantum atom optics is concerned with the statistical properties and correlations of matter-wave fields. A first step in this area is the measurement of reduced number fluctuations in a Bose-Einstein condensate partitioned into a series of optical potential wells.     

Direct observation of second-order atom tunnelling

Tunnelling of material particles through a classically impenetrable barrier constitutes one of the hallmark effects of quantum physics. When interactions between the particles compete with their mobility through a tunnel junction, intriguing dynamical behaviour can arise because the particles do not tunnel independently. In single-electron or Bloch transistors, for example, the tunnelling of an electron or Cooper pair can be enabled or suppressed by the presence of a second charge carrier due to Coulomb blockade. Here we report direct, time-resolved observations of the correlated tunnelling of two interacting ultracold atoms through a barrier in a double-well potential. For the regime in which the interactions between the atoms are weak and tunnel coupling dominates, individual atoms can tunnel independently, similar to the case of a normal Josephson junction. However, when strong repulsive interactions are present, two atoms located on one side of the barrier cannot separate, but are observed to tunnel together as a pair in a second-order co-tunnelling process. By recording both the atom position and phase coherence over time, we fully characterize the tunnelling process for a single atom as well as the correlated dynamics of a pair of atoms for weak and strong interactions. In addition, we identify a conditional tunnelling regime in which a single atom can only tunnel in the presence of a second particle, acting as a single atom switch. Such second-order tunnelling events, which are the dominating dynamical effect in the strongly interacting regime, have not been previously observed with ultracold atoms. Similar second-order processes form the basis of superexchange interactions between atoms on neighbouring lattice sites of a periodic potential, a central component of proposals for realizing quantum magnetism.     

Trapping an atom with single photons

The creation of a photon-atom bound state was first envisaged for the case of an atom in a long-lived excited state inside a high-quality microwave cavity. In practice, however, light forces in the microwave domain are insufficient to support an atom against gravity. Although optical photons can provide forces of the required magnitude, atomic decay rates and cavity losses are larger too, and so the atom-cavity system must be continually excited by an external laser. Such an approach also permits continuous observation of the atom's position, by monitoring the light transmitted through the cavity. The dual role of photons in this system distinguishes it from other single-atom experiments such as those using magneto-optical traps, ion traps or a far-off-resonance optical trap. Here we report high-finesse optical cavity experiments in which the change in transmission induced by a single slow atom approaching the cavity triggers an external feedback switch which traps the atom in a light field containing about one photon on average. The oscillatory motion of the trapped atom induces oscillations in the transmitted light intensity; we attribute periodic structure in intensity-correlation-function data to 'long-distance' flights of the atom between different anti-nodes of the standing-wave in the cavity. The system should facilitate investigations of the dynamics of single quantum objects and may find future applications in quantum information processing.