| Abstract: | The stable tribridged dicopper(I) carboxylate complexes Cu2(μ‐dppm)2(μ‐O2CR)]BF4 (RCO2 ? = 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 CH2Cl2. From the equilibrium mixtures containing MM and NN with MM/NN = 1:1, nine 2:1 oligomers (( m1 )2(μ‐bpy)](BF4)2 ( o1a (BF4)2), ( m3 )2(μ‐bpe)](BF4)2 ( o3c (BF4)2), ( m3 )2(μ‐tmp)](BF4)2 ( o3d (BF4)2), ( m4 )2(μ‐bpe)](BF4)2 ( o4c (BF4)2), ( m5 )2(μ‐bpy)](BF4)2 ( o5a (BF4)2), ( m5 )2(μ‐tmp)](BF4)2 ( o5d (BF4)2), ( m6 )2(μ‐bpa)](BF4)2 ( o6b (BF4)2), ( m7 )2(μ‐bpy)](BF4)2 ( o7a (BF4)2), ( m7 )2(μ‐bpa)](BF4)2 ( o7b (BF4)2)), one 2:3 oligomer ({( m2 )(bpy)}2(μ‐bpy)](BF4)2 ( o2a (BF4)2)), and five 1:1 polymers (( m2 )(μ‐bpe)] n (BF4 ) n ( p2c (BF4 ) n ), ( m2 )(μ‐tmp)] n (BF4 ) n ( p2d (BF4 ) n ), ( m3 )(μ‐bpy)] n (BF4 ) n ( p3a (BF4 ) n ), ( m3 )(μ‐tmp)] n (BF4 ) n ( p3d (BF4 ) n ), ( m7 )(μ‐tmp)] n (BF4 ) n ( p7d (BF4 ) 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, {Cu2(μ‐dppm)2(μ‐O2CR)}2(μ‐NN)]2+ and {Cu2(μ‐dppm)2(μ‐O2CR)(NN)}2(μ‐NN)]2+), in dynamic equilibrium. The oligomers (such as o3d (BF4)2) can serve as seeds to induce the formation of soluble coordination polymers as crystals (such as p3d (BF4)n ). |
