Reactivity of a Cadmium–Terpyridine Complex: [Cd( L 1 )( NO 3 ) 2 ( H 2 O )] ( L 1 = (4′‐(4‐bromophenyl)‐2,2′:6′,2″‐terpyridine)

A novel pincer‐type ligand L 2 (4′‐(4‐(6‐methoxypyridin‐3‐yl)phenyl)‐2,2′:6′,2″‐terpyridine), a terpyridine derivative, was prepared by Suzuki–Miyaura CC coupling. Under heating conditions in ethanol, ligands L 1 (4′‐(4‐bromophenyl)‐2,2′:6′,2″‐terpyridine) and L 2 reacted with Cd(NO 3 ) 2 ·4H 2 O to produce [Cd(L 1 )(NO 3 ) 2 (H 2 O)] ( 1 ) and [Cd(L 2 )(NO 3 ) 2 (H 2 O)]·(H 2 O) ( 2 ), respectively. In complexes 1 and 2 , the seven‐coordinate cadmium metal is coordinated to one terpyridine ligand, two nitrato ligands, and an aqua ligand. Under heating conditions in acetonitrile at 120 °C, complex 1 was converted into a 1:1 mixture ( 3 ) of [Cd 2 L 2 (NO 3 ‐ κ 3 O,O′,O″)(NO 3 ‐ κ 2 O,O′) 3 ] ( 3a ) and [CdL(NO 3 ‐ κ 2 O,O′) 2 ] ( 3b ). When complex 1 was treated with 4,4′‐bipyridine (bpy) under hydrothermal conditions, a one‐dimensional linear coordination polymer [[Cd(L 1 )(bpy)(NO 3 )](NO 3 )(H 2 O) 2 ] ∞ ( 4 ) was produced. Complex 1 reacted with 4‐(( E )‐2‐(pyridin‐4‐yl)vinyl)pyridine (bpe) in ethanol under microwave‐heating conditions to produce a dimeric complex [Cd 2 (L 1 ) 2 (bpe)(EtOH) 2 (NO 3 ) 2 )]·(NO 3 ) 2 ( 5 ). Solid‐state photoluminescent spectra of all complexes displayed a ligand‐based π–π* emission band.