New halo(pseudohalo)cadmates templated by protonatated N-heterocyclic/diamine molecules

Abstract

At ambient temperature, with various mono(di)protonated N-heterocyclic or diamine molecules as the cations, seven new halo(pseudohalo)cadmates [H₂(bpee)][Cd(SCN)₄] (bpee = 1,2-bis(4-pyridyl)ethene) 1, [H₂(bpyp)][CdBr₂(SCN)₂] (bpyp = 1,2-bis(4-pyridyl)propane) 2, [H₂(mbcha)][Cd₃Br₂(SCN)₆] (mbcha = 4,4′-methylenebis(cyclohexylamine)) 3, [(Hdabco)₂Cd₃(SCN)₈] (dabco = 1,4-diazabicyclo[2,2,2]octane) 4, [H₂(bp)][Cd(SeCN)₄] (bp = 4,4′-bipiperidine) 5 [H₂(pdma)][Cd(SeCN)₄]·2H₂O (pdma = 1,4-phenylenedimethanamine) 6 and [H₂(4,4′-dtdpy)][Cd₂Br₆] (dtdpy = dithioidipyridine) 7 were obtained. X-ray analysis revealed that (i) compound 1 possesses a three-dimensional (3D) supramolecular network structure with the one-dimensional (1D) channels, constructed from the inorganic [Cd(SCN)₄]²⁻ chains by weak S⋯S interactions. The H₂(bpee)²⁺ molecules occupy the space of the channels; (ii) with H₂(mbcha)²⁺ as the cation, the anion [Cd₃Br₂(SCN)₆]²⁻ of compound 3 exhibits a 1D ribbon structure, which can be described as a lengthways packing of planar bi-bridged trimers; (iii) compound 4 is the first example of the cation-controlled 3D thiocyanatocadmate with a composition [Cd₃(SCN)₈]²⁻; (iv) with H₂(4,4′-dtdpy)²⁺ as the cation, the anion [Cd₂Br₆]²⁻ of compound 7 also shows a 1D ribbon structure. This ribbon can be described as a transverse stacking of two planar bi-bridged single chains; (v) the ribbons of compounds 3 and 7 can be visualized as a slice of the two dimensional (2D) CdX₂ layer; (vi) in compounds 2, 3, 5, 6 and 7, the organic molecules as the linkers extend the inorganic anionic moieties into various 2D supramolecular layer networks.