The role of intermolecular interactions in the assemblies of Fe-II and Co-II tetrakis-isothiocyanatometalates with tris(1,10-phenanthroline)-Ru-II: Crystal structures of two dual-metal assemblies featuring octahedral cationic and tetrahedral anionic

摘要

Two new dual-metal assemblies: 2[Ru(phen)(3)](2+)center dot [Fe(SCN)(4)](2-)center dot 2SCN(-)center dot 4H(2)O 1 and [Ru(Phen)(3))(2+) [Co(SCN)(4)](2-) 2, (phen: 1,10-phenanthroline). have been prepared and their structures were characterized by X-ray diffraction. In 1,the cationic octahedral enantiomers are arranged with a Lambda Delta Lambda Delta Lambda sequence supported by pi-pi stacking and the anionic inorganic tetrahedral units are oriented between these stacks by interacting with the nearby water molecules through strong O-H center dot center dot center dot O and O-H center dot center dot center dot S hydrogen bonds. In 2, homochiral double helices in the b-direction are revealed, with tetrakis-isothiocyanate Co-II anions arranged in the crystal to furnish one-dimensional (1D)-helical chains with S center dot center dot center dot S intermolecular interactions at 3.512(2) and 3.966(2) A supporting [Ru(phen)(3)](2+) Lambda- and Delta-helices with Ru center dot center dot center dot Ru shortest distance of 8.676(7) A. In both 1 and 2, the supramolecular assembly is maintained by C-H center dot center dot center dot S hydrogen bonds extending between the phenanthroline aromatic carbons in the cationic nodes and the sulphur atoms of the isothiocyanates anions. Analysis of S center dot center dot center dot S interactions in isothiocyanate containing compounds using Cambridge structural database (CSD) showed an angle dependence categorizing these interactions into "type-I" and "type-II". (C) 2008 Elsevier Inc. All rights reserved.