Unusual demetalation of iron from [2]ferrocenophane skeleton of di‐nuclear ferracycle carbonyl complex

Photolysis of a hexane solution containing 1,1′‐ bis (trimethylsilylethynyl)ferrocene ( 1 ) and Fe (CO) 5 , under argon at 0 °C led to the formation of dinuclear complexes [Fe (CO) 2 {η 2 :η 2 – C (SiMe 3 ) = C(C 5 H 4 )FeC(C 5 H 4 ) = C (SiMe 3 )Fe (CO) 3 }–μ–CO] ( 2 ) and [Fe (CO) 2 {η 2 :η 2 –C (SiMe 3 ) = C(C 5 H 5 )–C(C 5 H 5 ) = C (SiMe 3 )Fe (CO) 3 }–μ–CO] ( 3 ). DFT calculations support the experimentally observed demetalation of ferrocene unit of 2 to 3 in presence of water. These compounds were comprehensively characterized by IR and 1 H and 13 C NMR spectroscopy and crystallographically ( 1 and 3 ).