Chapter 17
Downloaded by UNIV MASSACHUSETTS AMHERST on October 7, 2012 | http://pubs.acs.org Publication Date: November 29, 1996 | doi: 10.1021/bk-1996-0653.ch017
New Aspects of Heterometallic Copper (Silver) Cluster Compounds Involving Sulfido Ligands Xiantao Wu, Qun Huang, Quanming Wang, Tianlu Sheng, and Jiaxi Lu State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China The reactivity of sulfido ligands with different coordination configurations are systematically introduced leading to "unit construction", as a convenient method for designed synthesis of some heterometallic copper(silver)-sulfur cluster compounds. Heterometallic copper(silver)-sulfur cluster crystals with acentric space groups as potential precursors of crystal materials with non-linear physical properties are discussed. Discussions of synthetic methods and crystal structures for larger M-Cu-S cluster derivatives containing a square-type unit {M4Cu4S12} (M = Mo, W) are also provided. Additionally, polymeric M-Ag-S cluster complexes and the coexistence of polymeric cluster anions and hydrogen-bond supramolecular structure cations are rudimentarily explored. In recent years, the synthetic and structural chemistry of heterometallic copper (silver)-sulfur cluster compounds has developed rapidly (7). There are at least three factors stimulating this rapid development; i) the biological Mo-Cu antagonism (2-5) and the desire to produce analogues of active sites of metal enzymes (4); ii) the rich structural variety of complexes of this kind (1-4); iii) the nonlinear optical properties of transition metal sulfido cluster compounds (5-8). "Unit Construction": Designed Synthesis of Some Heterometallic Copper(SUver)-Sulfur Cluster Compounds (9) The Coordination Configuration of the Sulfido Ligand and Constructive Reactivity. "Unit construction" is a convenient method for the rational synthesis of transition metal clusters using reactivefragmentsas building blocks. It has been shown that the "unit", which contains sulfido ligand(s) with lone-pair electrons and unsaturated coordination, may add to another metal complex that has unsaturated coordination positions or easily displaceable ligand(s). In table I, the relationship between the six coordination configurations for the sulfido ligands is concisely described. Their constructive reactivity is summarized below. 0097-6156/96/0653-0282$15.00/0 © 1996 American Chemical Society In Transition Metal Sulfur Chemistry; Stiefel, E., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 1996.
17. WU ET AL.
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Heterometallic Copper (Stiver) Cluster Compounds 2
Downloaded by UNIV MASSACHUSETTS AMHERST on October 7, 2012 | http://pubs.acs.org Publication Date: November 29, 1996 | doi: 10.1021/bk-1996-0653.ch017
1) . Terminal sulfido ligand (term-S). A typical example is MoS4 ~. The bond between the Mo atom and the sulfido ligand is a double bond. The terminal sulfido ligand has potent constructive value, because it is only coordinated by one metal atom and it contains two lone-pairs of electrons. 2) . P2-Bridging sulfido ligand (p2-S). This type of coordination configuration can be classified into three subtypes [(a), (b), (c) below]. Table I. The relationship between coordination configuration of the sulfido ligands and constructive reactivity. (Reproduced with permissionfromreference 9. Copyright 1994 Plenum.) No. 1
No. of lone- C. N . of pair electrons S atoms
Type of coordination
Coordination configuration
term-S
M=S
4
1
MoS "
20
/
