Syntheses and crystal structures of three novel oxalate coordination compounds: RbCo(CO)·4HO, RbCoCl(CO) and KLiCu(CO)·2HO.

Single crystals of three novel transition-metal oxalates, dirubidium di-aqua-dioxalatocobalt(II) dihydrate or dirubidium cobalt(II) bis-(oxalate) tetra-hydrate, Rb[Co(CO)(HO)]·2HO, (I), -poly[dirubidium [[di-chlorido-cobalt(II)]-μ-oxalato]] or dirubidium cobalt(II) dichloride oxalate, {Rb[CoCl(CO)]} , (II), and poly[dipotassium [tri-μ-oxalato-copper(II)dilithium] dihydrate] or dipotassium dilithium copper(II) tris-(oxalate) dihydrate, {K[LiCu(CO)]·2HO} , (III), have been grown under hydro-thermal conditions and their crystal structures determined using single-crystal X-ray diffraction. The structure of (I) exhibits isolated octa-hedral [Co(CO)(HO)] units, whereas (II) consists of chains of Co ions bridged by bidentate oxalato ligands and (III) displays a novel tri-periodic network of Li and Cu ions linked by oxalato bridging ligands.