Stepwise and Self‐Assembly Synthesis of Tetranuclear Iron–Thiolate–Diisocyanide Metallocyclophane Complexes

Treatment of known complex [ Cp 2 Fe 2 (μ‐ SEt ) 2 ( CH 3 CN ) 2 ]( BF 4 ) 2 ( 1 ( BF 4 ) 2 ) with 2 equiv of 1,4‐bis(isocyanomethyl)benzene (1,4‐ CNCH 2 C 6 H 4 CH 2 NC ; L1 ) or 4,4′‐diisocyanophenyl ether (4,4′‐ CNC 6 H 4 OC 6 H 4 NC ; L2 ) result in the formation of two new‐type diisocyanide complexes [ Cp 2 Fe 2 (μ‐ SEt ) 2 (1,4‐ CNCH 2 C 6 H 4 CH 2 NC ) 2 ]( BF 4 ) 2 ( 2a ( BF 4 ) 2 ) or [ Cp 2 Fe 2 (μ‐ SEt ) 2 (4,4′‐ CNC 6 H 4 OC 6 H 4 NC ) 2 ]( BF 4 ) 2 ( 2b ( BF 4 ) 2 ), respectively. The new‐type 24‐membered ring tetranuclear iron–thiolate–aryldiisocyanide metallocyclophane complex [ Cp 4 Fe 4 (μ‐ SEt ) 4 (μ‐1,4‐ CNCH 2 C 6 H 4 CH 2 NC ) 2 ]( BF 4 ) 4 ( 3a ( BF 4 ) 4 ) has been synthesized by using a self‐assembly reaction between equimolar amounts of 1 ( BF 4 ) 2 and 1,4‐bis(isocyanomethyl)benzene or by a stepwise route involving mixing a 1:1 molar ratio of complexes 1 ( BF 4 ) 2 and 2a ( BF 4 ) 2 . A similar approach was used through the application of equal molar ratio of complexes 1 ( BF 4 ) 2 and 2b ( BF 4 ) 2 to give a 30‐membered ring tetranuclear iron–thiolate–aryldiisocyanide metallocyclophane complex [ Cp 4 Fe 4 (μ‐ SEt ) 4 (4,4′‐ CNC 6 H 4 OC 6 H 4 NC ) 2 ][ BF 4 ] 4 ( 3b ( BF 4 ) 4 ). The spectroscopic and electrochemical properties of four iron–sulfur core complexes were determined.