An unusual nitroso center dot center dot center dot nitroso interaction in the coordination polymer structures of Ni(II) and Co(II) complexes with the alpha,omega-bis(benzotriazoloxy)alkane system

作者：Saha Sandeepta^*; Sasmal Ashok; Pilet Guillaume; Bauza Antonio; Frontera Antonio; Mitra Samiran

来源：CrystEngComm, 2014, 16(4): 654-666.

DOI：10.1039/c3ce41765d

A novel type of NO center dot center dot center dot NO supramolecular interaction is reported for the first time. Three new polymeric coordination complexes, two nickel(II) complexes, {[Ni(mu-L-1)(2)(NCS)(2)]}(n), (1) {[Ni(mu-L-2)(2)(NCS)(2)]}(n), (2) and a cobalt(II) complex {[Co(mu-L-3)(2)(NCS)(2)]}(n) (3) have been synthesized with the organic ligand alpha,omega-bis(benzotriazoloxy)alkane (L-1 = 1,3-bis(benzotriazol-1-yl)-1,3-dioxapropane; L-2 = 1,5-bis (benzotriazol-1-yl)-1,5-dioxapentane; L-3 = 1,6-bis(benzotriazol-1-yl)-1,6-dioxahexane) and thiocyanate as counterions. The complexes were characterized by various physical measurements such as elemental analysis, FT-IR, UV-Vis, NMR and mass spectroscopy. The single crystal X-ray analysis revealed that complexes 1 and 2 have a 1D coordination polymer helical structure whereas complex 3 has a 2D polymer anti corrugate structure. Complexes 2 and 3 were found to be involved in packing in the crystal structures by a very unusual anti-parallel strong NO center dot center dot center dot NO interaction. In addition, the pi-acidity of the triazole ring moiety increased upon the coordination of the Ni ion which led to the establishment of lone pair-pi (lp-pi) interactions. Moreover, all of the complexes show different intermolecular interactions (H-bonds, pi-pi, lone pair-pi and anti-parallel NO center dot center dot center dot NO) whose energetics and role in the crystal packing have been evaluated with theoretical DFT calculations.

• 出版日期2014