Heterobimetallics of nickel-iron dinitrosyl: Electronic control by chelateand diatomic ligands

Reaction of [PPN][Fe(NO)(2)(SePh)(2)] (1) with dimeric [Ni(mu-SCH2CH2S)](2) in the presence of additional NO2- produced the neutral heterobimetallic [ (ON)Ni{(mu-SCH-CH2)(2)S}Fe(NO)(2)] complex (2). The X-ray crystal structure s of I and 2 show distorted tetrahedral iron dinitrosyl groups, assigned ac cording to the Feltham-Enemark notation as {Fe(NO)(2)}(9). The Fe-NO bonds are off linearity by an average of approximate to 10 degrees for compounds I and 2, while a more linear Ni-NO coordination with a Ni-NO distance of 1. 644(2) Angstrom was found in 2. The nu(NO) value of complex 2 is consistent with an assignment for {Ni(NO)}(9) of Ni-0(NO)(+) as is known for analogou s phosphine derivatives, P3Ni0(NO)(+). EPR signals of g values = 2.02-2.03 confirmed the existence of the odd electron in the chalcogenated {Fe(NO)(2) }(9) compounds. Two {Fe(NO)(2)}(10) complexes coordinated by the nickel(II) dithiolate, (bismercaptoethsnediazacyclooctane)nickel(II), (Ni-1)Fe(CO)(NO )(2) and (Ni-1)Fe(NO)(2), were prepared for comparison to the Ni-0(NO)(+) d erivative and other monomeric and homodimetallic derivatives of the Fe(NO)I fragment. While the oxidation level of Fe(NO)(2) is the primary determinan t of nu(NO) values. they are also highly sensitive to ancillary ligands and , thereby, the distal metal influence through the bridging thiolate donor.