Copper complexes infinite chains

Heating [Zn(dmpz)2(Hdmpz)]2, 31, at 240°C (see Fig. 5) caused the loss of Hdmpz and the formation of the species [Zn(dmpz)2] , 25 (42). Complex 25 is assumed to be polymeric, with an infinite chain structure, by analogy with the known structure of other binary copper(II) pyrazolates (35). 

In terms of Pearson s hard-soft acid-base principle, the soft Lewis acid copper ion is not compatible with the hard base H20 molecule, but a recent article provided the first example of a copper(I)-water bond (240). The novel copper complex with 2,3-diphenylquinoxaline (L 1), [Cu(L91)(H20)]C104, is diamagnetic and indefinitely stable in air in the solid state. Its structure consists of an infinite polymeric cationic chain in which adjacent metal centers are bridged by the aro-... 

Four silver(I) and copper(I) complexes of 140 have been synthesized and their structures determined by X-ray diffraction. Different anion coordinating abilities lead to two kinds of infinite chains in complexes 168 and 169 in which diketo ligand 140 exhibits different coordinating modes. In metallacyclophanes 170 and 171, similar non-coordinating... 

Complexes 19-22 were reported to most likely have structures involving extended chains of copper ions linked by double pyrazolate bridges in analogy with the structures of species [Cu(4-Xpz)2] , where X = H, Me, and Cl (35, 36). However, it is possible that the presence of methyl substituents in the 3,5-positions of the heterocyclic ring, causing steric hindrance, prevents the formation of an infinite polymeric chain. 

In an attempt to use dicopper(I) complex unit as building block for synthesis of metal-containing polymers, Kitagawa reported his interesting results in synthesis and structural characterization of an infinite stair-type chain compound (235). The complex of thiochrome (L88) [C CLae KClO was prepared by reduction of copper(II) perchlorate followed by reaction with the ligand. The structure contains a di-nuclear cationic unit in which the two T-shaped metal ions are doubly bridged by two thiochrome molecules with extremely short Cu Cu... 

Iodide complexes also adopt different structural types. The [Cu(S2CNBu2)2] [I3] complex polymeric with no anion-cation interactions (S) (320), while [Cu(S2CNEt2)2][l3] is also polymeric, but adopts structural type (W) to form infinite ladder chains in which bis(dithiocarbamate) units are separated by I3 anions (324). In contrast, [Cu(S2CNPt2)2][I5] adopts a type (X) structure in which the copper center is live coordinate, an is bound to the central atom of the 15 anion [Cu- I 3.665(4) A] (318). 

---