Structure-directing role of the asymmetric methyl-4-(pyrimidin-2-ylcarbamoyl)benzoate ligand in the self-assembly of Co(II), Ni(II), Cu(II) and Cu(I) complexes

The reactions of methyl-4-(pyrimidin-2-ylcarbamoyl)benzoate ( L ) with Co(II), Ni(II), Cu(II) and Cu(I) metal salts afforded [Co( L ) 2 (CH 3 OH) 2 ](ClO 4 ) 2 ( 1 ), [Co( L ) 2 (CH 3 OH) 2 ](BF 4 ) 2 ( 2 ), [Ni( L ) 2 (CH 3 OH) 2 ](BF 4 ) 2 ( 3 ), [Cu( L ) 2 (ClO 4 ) 2 ]·2CH 3 OH ( 4 ), [Cu( L ) 2 (BF 4 ) 2 ]·2CH 3 OH ( 5 ), [Cu( L ) 2 Br 2 ]·CH 3 OH ( 6 ), [Cu 2 ( L )Cl 4 ·CH 3 CN] ∞ ( 7 ), [Cu 3.5 ( L )Br 4 ·0.5C 2 H 5 OC 2 H 5 ] ∞ ( 8 ) and [Cu 2 ( L )I 2 ] ∞ ( 9 ), which have been structurally characterized by X-ray crystallography. Four types of ligand conformation-coordination mode, cis -bidentate, cis -tridentate, trans -bidentate and trans -tridentate, are observed for the L ligand in these complexes, resulting in mononuclear structures for 1 – 6 , layer structures for 7 and 8 and a chain structure for 9 . C–H⋯π and π⋯π interactions and various hydrogen bonds are found in these complexes that extend the dimensionalities of the structures, and the structural types of the copper halide aggregates in 7 – 9 are unique.