Linking Tribridged Dicopper Complexes with Neutral Dipyridyl Compounds to Coordination Oligomers and Polymers

The stable tribridged dicopper(I) carboxylate complexes [Cu 2 (μ‐dppm) 2 (μ‐O 2 CR)]BF 4 (RCO 2 − = formate (OFc − ), m1 ; acetate (OAc − ), m2 ; benzoate (OBAc − ), m3 ; o ‐toluate (O2TAc − ), m4 ; p ‐toluate (O4TAc − ), m5 ; 4‐phenylbutyrate (O4PBAc − ), m6 ; 2‐nitrobenzoate (O2NBAc − ), m7 ), abbreviated as MM, and neutral dipyridyl compounds (NN; NN = 4,4′‐bipyridine (bpy), 1,2‐bis(4‐pyridyl)ethane (bpa), trans ‐1,2‐bis(4‐pyridyl)ethylene (bpe), 4,4′‐trimethylenedipyridine (tmp)) can form dynamic equilibria in CH 2 Cl 2 . From the equilibrium mixtures containing MM and NN with MM/NN = 1:1, nine 2:1 oligomers ([( m1 ) 2 (μ‐bpy)](BF 4 ) 2 ( o1a (BF 4 ) 2 ), [( m3 ) 2 (μ‐bpe)](BF 4 ) 2 ( o3c (BF 4 ) 2 ), [( m3 ) 2 (μ‐tmp)](BF 4 ) 2 ( o3d (BF 4 ) 2 ), [( m4 ) 2 (μ‐bpe)](BF 4 ) 2 ( o4c (BF 4 ) 2 ), [( m5 ) 2 (μ‐bpy)](BF 4 ) 2 ( o5a (BF 4 ) 2 ), [( m5 ) 2 (μ‐tmp)](BF 4 ) 2 ( o5d (BF 4 ) 2 ), [( m6 ) 2 (μ‐bpa)](BF 4 ) 2 ( o6b (BF 4 ) 2 ), [( m7 ) 2 (μ‐bpy)](BF 4 ) 2 ( o7a (BF 4 ) 2 ), [( m7 ) 2 (μ‐bpa)](BF 4 ) 2 ( o7b (BF 4 ) 2 )), one 2:3 oligomer ([{( m2 )(bpy)} 2 (μ‐bpy)](BF 4 ) 2 ( o2a (BF 4 ) 2 )), and five 1:1 polymers ([( m2 )(μ‐bpe)] n (BF 4 ) n ( p2c (BF 4 ) n ), [( m2 )(μ‐tmp)] n (BF 4 ) n ( p2d (BF 4 ) n ), [( m3 )(μ‐bpy)] n (BF 4 ) n ( p3a (BF 4 ) n ), [( m3 )(μ‐tmp)] n (BF 4 ) n ( p3d (BF 4 ) n ), [( m7 )(μ‐tmp)] n (BF 4 ) n ( p7d (BF 4 ) n )) were obtained as single crystals, and their structures were determined by X‐ray crystallography. Both experimental and theoretical results support the presence of two oligomeric species, [{Cu 2 (μ‐dppm) 2 (μ‐O 2 CR)} 2 (μ‐NN)] 2+ and [{Cu 2 (μ‐dppm) 2 (μ‐O 2 CR)(NN)} 2 (μ‐NN)] 2+ ), in dynamic equilibrium. The oligomers (such as o3d (BF 4 ) 2 ) can serve as seeds to induce the formation of soluble coordination polymers as crystals (such as p3d (BF 4 ) n ).