Dimolybdenum Bis-2,4,6-triisopropyl-benzoate Bis-4-isonicotinate: A Redox Active Analogue of 4,4′-Bipyridine with Ambivalent Properties

The reaction between Mo-2(TiPB)(4) and 4-iso-nicotinic acid (2 equiv) in ethanol leads to the formation of trans-Mo-2(TiPB)(2)(nic)(2), 1, where TiPB = 2,4,6-triisopropylbenzoate and nic = 4-isonicotinate. The molecular structures of I and I-2DMSO were determined in the solid state by a single-crystal X-ray study, and its electronic structure was determined by DFT calculations on a model compound, where formate ligands were substituted for the bulky TiPB. The physicochemical properties of I are reported, and its potential as a redox active building block, a quasi-metalloorganic analogue of 4,4'-bipyridine, is described in the synthesis of molecular and solid-state assemblies. The molecular structure of I in the solid state consists of a 3-dimensional network in which each unit of Mo-2(TiPB)(2)(nic)(2) acts as a donor and acceptor via N to Mo coordination. In the structure of I.2DMSO, the DMSO ligands coordinate axially with the Mo-Mo bond via oxygen, The reaction between I and Rh-2(O2CMe)(4) is shown to give a 1-D polymeric chain in the solid state: [{Rh-2(O2CMe)(4)}{Mo-2(TiPB)(2)(nic)2}](infinity), II. A similar structure was found for the product involving Rh-2(O2CCMe3)(4). Evidence is also reported for the formation of [(1,5-COD)MePt](2)[mu-Mo-2(TiPB)(2)(nic)(2)](PF6)(2), III, and [(1,5-COD)Pt(mu-I)(PF6)(2)](n).