Preparation, Crystal Structure, and Properties of Five Metal‐Organic Complexes Based on a Triangular Nonplanar Carboxylate Ligand

A nonplanar triangular carboxylate ligand has been synthesized and applied to assemble metal‐organic frameworksunder hydro‐ or solvothermal conditions. Five new metal‐organic complexes, [H 2 N(CH 3 ) 2 ] 2 [Cd(HTMBTC) 2 ] · 2H 2 O · dmf ( 1 ), [Cu 3 (TMBTC) 2 (2,2′‐bpy) 2 ] · H 2 O ( 2 ), [Zn 3 (TMBTC) 2 (H 2 O) 2 ] · H 2 O ( 3 ), [Cd 3 (TMBTC) 2 (H 2 O) 4 ] · 4H 2 O ( 4 ), and [Cu 3 (TMBTC) 2 ]( 5 ), (dmf = dimethylformamide; TMBTC = 2,4,6‐trimethylbenzene‐1,3,5‐tricarboxylic acid; bpy = bipyridine) were crystallized; they possess four different structural types. In 1 , the nonplanar carboxylate ligand connects the cadmium ion to give rise to a 2D (4,4) topological layer that contains two vertical left‐ and right‐handed helical chains. In 2 , the carboxylate ligands first link the copper ions to generate a 1D tubular unit, which can be considered the basic building block. The 1D tubular units are further connected by the ligand to form a 2D layer structure. Complexes 3 and 4 have similar structural types. The zinc and cadmium ions are connected by the ligand to form a bilayer framework that contains double (6,3) topological nets. Different from complexes 1 – 4 , complex 5 has a 3D framework. The copper ions are first connected by the ligand to generate a bilayer structure that contains double (6,3) nets, which are further connected by sharing the copper ion to form the final 3D framework. Photoluminescence measurements of 1 , 3 , and 4 in the solid state at room temperature show that all three coordination networks exhibit similar, strong luminescence, which can be assigned to an intraligand π → π* transition.