Novel dithioether–silver(<scp>i</scp>) coordination architectures: structural diversities by varying the spacers and terminal groups of ligands
作者:Jian-Rong Li、Xian-He Bu、Jiao Jiao、Wen-Ping Du、Xiu-Hua Xu、Ruo-Hua Zhang
DOI:10.1039/b416576b
日期:——
An investigation into the dependence of the framework formation of coordination architectures on ligand spacers and terminal groups was reported based on the self-assembly of AgClO4 and eight structurally related flexible dithioether ligands, RS(CH2)nSR (Lan, R = ethyl group; Lbn, R = benzyl group, n
= 1â4). Eight novel metalâorganic architectures, [Ag(La1)3/2ClO4]n
(1a), [Ag2(La2)2(ClO4)2]2
(2a), [AgLa3ClO4]n
(3a), [Ag(La4)2]ClO4}n
(4a), [AgLb1ClO4]2
(1b), [Ag(Lb2)2]ClO4
(2b), [Ag(Lb3)3/2(ClO4)1/2](ClO4)1/2}n
(3b) and [Ag(Lb4)3/2ClO4]n
(4b), were synthesized and structurally characterized by X-ray crystallography. Structure diversities were observed for these complexes: 1a forms a 2-D (6,3) net, while 2a is a discrete tetranuclear complex, in which the AgI ion adopts linear and tetrahedral coordination modes, and the S donors in each ligand show monodentate terminal and μ2-S bridging coordination fashions; 3a has a chiral helical chain structure in which two homo-chiral right-handed single helical chains (AgâLa3â)n are bound together through μ2-S donors, and simultaneously gives rise to left-handed helical entity (AgâSâ)n. In 4a, left- and right-handed helical chains formed by the ligands bridging AgI centers are further linked alternately by single-bridging ligands to form a non-chiral 2-D framework. 1b has a dinuclear structure showing obvious ligand-sustained AgâAg interaction, while 2b is a mononuclear complex; 3b is a 3-D framework formed by ClO4â linking the 2-D (6,3) framework, which is similar to that of 1a, and 4b has a single, double-bridging chain structure in which 14-membered dinuclear ring units formed through two ligands bridging two AgI ions are further linked by single-bridging ligands. In addition, a systematic structural comparison of these complexes and other reported AgClO4 complexes of analogous dithioether ligands indicates that the ligand spacers and terminal groups take essential roles on the framework formation of the AgI complexes, and this present feasible ways for adjusting the structures of such complexes by modifying the ligand spacers and terminal groups.
基于 AgClO4 和八种结构相关的柔性二硫醚配体 RS(CH2)nSR(Lan,R = 乙基;Lbn,R = 苄基,n = 1â4)的自组装,报告了配位体系结构的框架形成对配体间隔物和末端基团的依赖性的研究。八种新型金属有机结构:[Ag(La1)3/2ClO4]n (1a)、[Ag2(La2)2(ClO4)2]2 (2a)、[AgLa3ClO4]n (3a)、[Ag(La4)2]ClO4}n (4a)、[AgLb1ClO4]2 (1b)、合成了[Ag(Lb2)2]ClO4 (2b)、[Ag(Lb3)3/2(ClO4)1/2](ClO4)1/2}n (3b) 和 [Ag(Lb4)3/2ClO4]n (4b)。这些复合物的结构具有多样性:1a 形成了一个二维 (6,3) 网状结构,而 2a 则是一个离散的四核配合物,其中 AgI 离子采用线性和四面体配位模式,而每个配体中的 S 给体都呈现单价末端配位和 δ2-S 桥接配位方式;3a 具有手性螺旋链结构,其中两条同手性右手单螺旋链(AgâLa3â)n 通过δ¼2-S 供体结合在一起,同时产生左手螺旋实体(AgâSâ)n。在 4a 中,由桥接 AgI 中心的配体形成的左手和右手螺旋链通过单桥接配体进一步交替连接,形成一个非手性的二维框架。1b 具有双核结构,显示出明显的配体与 AgâAg 的相互作用,而 2b 则是单核复合物;3b 是 ClO4â 连接二维(6,3)框架形成的三维框架,与 1a 相似,而 4b 具有单双桥链结构,其中通过两个配体桥接两个 AgI 离子形成的 14 元双核环单元通过单桥接配体进一步连接。此外,将这些配合物与其他已报道的类似二硫醚配体的 AgClO4 配合物进行系统的结构比较表明,配体的间隔和末端基团对 AgI 配合物的框架形成起着至关重要的作用,这为通过改变配体的间隔和末端基团来调整这类配合物的结构提供了可行的方法。