Two-dimensional metal-organic framework constructed from 4,4′-bipydine and 1,2,4-benzenetricarboxylate: Synthesis, structure and magnetic properties

Abstract

Two new copper coordination polymers generated from mixed organic ligands 4,4′-bipydine and 1,2,4-benzenetricarboxylate [Cu 3(1,2,4-BTC) 2(4,4′-bipy)(H 2O) 4] 1 and [Cu(1,2,4-HBTC)(4,4′-bipy)] 2 (1,2,4-BTC=1,2,4-benzenetricarboxylate) have been prepared hydrothermally and characterized by single crystal X-ray diffraction. Compound 1 crystallizes in the noncentrosymmetric space group Fdd 2 , with a = 19.004 ( 3 ) Å , b = 26.711 ( 4 ) Å , c = 11.0770 ( 15 ) Å , V = 5622.8 ( 14 ) Å 3 , and Z = 8 . Its structure contains two different one-dimensional (1-D) chains for the Cu ions, namely [ Cu 2 ( 1 , 2 , 4 - BTC ) 2 ] n 2 n - and [ Cu ( 4 , 4 ′ - bipy ) ] n 2 n + ; the carboxylate of 1,2,4-BTC ligands links the two different 1-D chains into an interesting steplike neutral framework. Compound 2 crystallizes in the monoclinic space group P 2 1 / n , with a = 9.9806 ( 8 ) , b = 16.5512 ( 16 ) , c = 11.3109 ( 7 ) Å , β = 99.375 ( 5 ) ° , V = 1843.5 ( 3 ) Å 3 , Z = 4 . Its structure contains novel paddle-wheel clusters Cu 2(CO 2) 4(4,4′-bipy) 2 as SBUs which are further linked by monoprotonated 1,2,4-BTC ligands into a 2-D neutral framework. The magnetic behaviors of both compounds have been studied.