Influence of Lewis acid charge and proximity in Mo Mo⋯M linear chain compounds with M=Na + , Ca 2+ , Sr 2+ , and Y 3+

Abstract The syntheses, X-ray structural characterizations, and electrochemical properties of four new paddlewheel [MMo 2 (SNO5) 4 Cl] ( n −1)+ (M n +  = Na + , Ca 2+ , Sr 2+ , Y 3+ ; HSNO5 = monothiosuccinimide) compounds are described here. By changing the M n + cation charge and size, we demonstrate a method for easily tuning the Lewis acidity of the Mo Mo quadruple bond and the [Mo 2 ] 4+/5+ redox potential. As the charge of the M n + cation is increased, the distal Mo atom becomes more Lewis acidic, leading to a shorter Mo 2 –Cl bond distance, and the [Mo 2 ] 4+/5+ redox couple becomes less accessible. As the M n + ⋯Mo 2 distance is increased, the distal Mo atom becomes less Lewis acidic, leading to a longer Mo 2 –Cl bond distance.