Novel complexes of silver(I) sulfate with 1-methylimidazole-2-thione: structures and vibrational spectroscopy

Crystallization of silver(I) sulfate with the ligand 1-methylimidazole-2-thione ('Hmimt') from aqueous solution, instead of yielding the expected 1 : 6 Ag(2)SO(4) : Hmimt complex analogous to numerous other Ag(2)SO(4) : thiourea-based ligand (1 : 6) complexes, has resulted in novel polymeric forms, one of unusual stoichiometry. Ag(2)SO(4) : Hmimt (1 : 4) (center dot H(2)O) is of the form [center dot center dot center dot (mu-Hmimt)(2)Ag(mu-Hmimt)(2)Ag center dot center dot center dot](infinity|infinity)(SO(4)), with a one-dimensional polymeric cation. Ag(2)SO(4) : Hmimt (3 : 8) (center dot 9 1/2H(2)O) is a polymeric sheet structure containing Ag(12)(SO(4))(6)(Hmimt)(15) kernels linked by Hmimt ligands. The IR spectra of these compounds show unusually large shifts of the nu(NH) band due to the presence of N-H center dot center dot center dot O hydrogen bonding involving the N-H group of the ligand and the sulfate oxygen atoms. The complexes were also readily prepared by the solvent-assisted mechanochemical method, and the utility of this method for the preparation of deuterium-exchanged products for assistance in the assignment of the IR spectra is illustrated.