화학공학소재연구정보센터
Inorganic Chemistry, Vol.59, No.15, 11166-11173, 2020
Influence of the Molar Ratio and Solvent on the Coordination Modes of 1,7-Dibenzyl-4,10-bis(pyridin-4-ylmethyl)cyclen
The synthesis of a tetra-armed cyclen (L) with two benzyl groups at the 1- and 7-positions and two pyridin-4-ylmethyl groups at the 4- and 10-positions as side arms and the solvent- and/or molar-ratio-dependent coordination modes in the formation of silver(I) complexes are reported. H-1 NMR and cold-spray-ionization mass spectrometry studies suggest that a silver(I) complex with L gives different species depending on the molar ratio of silver ions used as the reactant. Furthermore, the conformation of cyclen in the one-dimensional (1D) coordination polymers, obtained using 2 equiv of silver(I), changes depending on the presence or absence of acetonitrile. When L was reacted with 1 and 2 equiv of silver(I) triflate in a mixed solvent system (CH2Cl2/CH3OH/CH3CN), a dimetallo[3.3]paracyclophane-like discrete cyclic dimer, [Ag2L2](OTf)(2) (1), and a 1D coordination polymer, [Ag2L(OTf)(2)(CH3CN)](n) (2), respectively, were obtained as single crystals. In the absence of acetonitrile, a zigzag 1D coordination polymer, {[Ag2L(OTf)]OTf center dot 3CH(2)Cl(2)} n (3), was obtained when 2 equiv of silver(I) was used. Molar-ratio-dependent structural changes were not observed when L was reacted with AgBF4 or AgPF6 in the CH2Cl2/CH3OH/CH3CN mixed-solvent system. The solvent effect on the coordination modes can be explained by the coordination ability of the solvents toward the metal cation affecting the conformation of the cyclen.