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首页> 外文期刊>Coordination chemistry reviews >Structure and magnetism of coordination polymers containing dicyanamide and tricyariomethanide
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Structure and magnetism of coordination polymers containing dicyanamide and tricyariomethanide

机译：含双氰胺和三氯甲基甲烷的配位聚合物的结构和磁性

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摘要

Coordination polymers containing dicyanamide (N(CN)_2~-, dca) or tricyanomethanide (C(CN)_3~-, tcm) bridging ligands are described from the perspective of their structure and magnetism. The binary compounds α-M(dca)_2 form an isostructural series (M = Cr, Mn, Fe, Co, Ni, Cu) having a single rutile-like network that involves μ_(1,3,5)-dca bridging. They display quite diverse types of long-range magnetic order viz. canted-spin antiferromagnets (Cr, Mn, Fe), ferromagnets (Co, Ni, Cu). An up-to-date review is given of the diverse range of physical measurements made on the α-M(dca)_2 series together with interpretations for the different net exchange coupling and consequent 3D order. The doubly interpenetrating rutile network M(tcm)_2 series generally do not show long-range order except for a few members at very low temperatures. The 'mixed' self-penetrating network compounds M(dca)(tcm) do show long-range order (M = Co, Ni), albeit at lower T_c values than for the M(dca)_2 parents. Modification of the M-dca networks is possible by incorporation of coligands into the structures. Ternary species of type M(dca)_2(L)_n, where L is a terminal (e.g. pyridine, MeOH) or a bridging (e.g. pyrazine, 4,4′-bipyridine) coligand, display a diverse range of 1D, 2D and 3D structural types. With a few exceptions, the large number of compounds structurally characterised contain μ_(1,5)-dca bridging and display very weak antiferromagnetic coupling (J < ca. ―1 cm~(-1)), typical of this bridging mode. Compounds such as Mn(dca)_2(pyrazine) display a magnetic phase transition at low temperatures. This is also the case in the isostructural 2D layer compounds M(dca)_2(H)_2O) · phenazine (M = Fe, Ni) which, perhaps not surprisingly, do not have coordinated phenazines but, rather, phenazines intercalated between layers of M(dca)_2(H_2O) in which μ_(1,3,5) and μ_(1,5)-dca bridging exists. Anionic networks of types M(dca)_3~- and M(dca)_4~(2-) formed by templation around cations of the organic (e.g. Ph_4E~+, R_4N~+) or inorganic (M(2,2′-bipyridine)_3~(2+)) types are described. The latter display no magnetic interactions between the weakly antiferromagnetically coupled anionic sub-lattice and the paramagnetic catiotiic sub-lattice.
机译：从结构和磁性的角度描述了含有双氰胺（N（CN）_2〜-，dca）或三氰甲酰胺（C（CN）_3〜-，tcm）桥联配体的配位聚合物。二元化合物α-M（dca）_2形成同构结构系列（M = Cr，Mn，Fe，Co，Ni，Cu），具有涉及μ_（1,3,5）-dca桥接的单个金红石状网络。它们显示了各种类型的远程磁阶即。倾斜自旋反铁磁体（Cr，Mn，Fe），铁磁体（Co，Ni，Cu）。对在α-M（dca）_2系列上进行的各种物理测量以及对不同净交换耦合和随之而来的3D顺序的解释进行了最新回顾。双互穿金红石网络M（tcm）_2系列通常不显示远距离有序，只有极低温度下的几个成员除外。 “混合的”自穿透网络化合物M（dca）（tcm）确实显示了远距离有序（M = Co，Ni），尽管其T_c值低于M（dca）_2母体。通过将大肠菌素掺入结构中，可以修饰M-dca网络。 M（dca）_2（L）_n型三元物种，其中L是末端（例如，吡啶，MeOH）或桥接（例如，吡嗪，4,4'-联吡啶）大肠杆菌，显示1D，2D和3D结构类型。除少数例外，结构上表征的大量化合物包含μ_（1,5）-dca桥联，并显示出非常弱的反铁磁耦合（J <约-1 cm〜（-1）），这是这种桥联模式的典型特征。诸如Mn（dca）_2（吡嗪）之类的化合物在低温下显示出磁性相变。在同构2D层化合物M（dca）_2（H）_2O）·吩嗪（M = Fe，Ni）中也是如此，也许并不奇怪，它们没有配位的吩嗪，而是插在层间的吩嗪M（dca）_2（H_2O）其中存在μ_（1,3,5）和μ_（1,5）-dca桥接。 M（dca）_3〜-和M（dca）_4〜（2-）型阴离子网络是通过模板化围绕有机（例如Ph_4E〜+，R_4N〜+）或无机（M（2,2'-描述了联吡啶）_3〜（2+））的类型。后者在弱反铁磁耦合的阴离子亚晶格和顺磁性阳离子亚晶格之间没有磁性相互作用。

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