d 8 ‐Eisennitrosylhydride

d 8 Iron Nitrosylhydride Complexes The nitrogen complex [(OC) 2 (Et 3 P) 2 Fe] 2 N 2 ( 1 ) reacts with carboxylic acids to form the complexes (OC) 2 (Et 3 P) 2 Fe(H)OC(O)R [R=4‐methoxyphenyl, 2a ; R=2,4‐dimethoxyphenyl, 2b ; R=2,4,6‐trimethoxyphenyl, 2c ; R – Ph, 2d ; R – CF 3 , 2e]. Treatment of 2 with N ‐methyl‐ N ‐nitroso‐ p ‐tolylsulfonamide produces the nitrosylcarboxylato complexes (OC)(ON)‐(Et 3 P) 2 FeOC(O)R ( 3a – d ) in addition to the side product Fe(NO) 2 (PEt 3 ) 2 ( 4 ) except for 2e which forms 4 exclusively. Reaction of 3 with LiAlH 4 yields the hydridonitrosyliron complex (OC)(ON)(Et 3 P) 2 FeH ( 5a ). A different synthetic route to the phosphorus donor‐substituted iron hydride complexes involves starting material (OC) 2 (L) 2 FeCl 2 [LPEt 3 , 6a ; L – PMe 3 , 6b ; LP(O i Pr) 3 , 6c ]. Compounds 6 react with t BuLi and NOBF 4 to form (OC)(ON)L 2 FeCl ( 7 ). Subsequent treatment with NaBH 4 gives (OC)(ON)(L) 2 FeH [LPEt 3 , 5a ; LPMe 3 , 5b ; LP(O i Pr) 3 , 5c ]. The structures of 5b and 7a are determined by X‐ray crystallography.