Nitrosyl and carbene iron complexes bearing a κ3-SNS thioamide pincer type ligand†
Tatsuya Suzuki,Jun Matsumoto,Yuji Kajita,Tomohiko Inomata,Tomohiro Ozawa,Hideki Masuda
Dalton Transactions Pub Date : 11/03/2014 00:00:00 , DOI:10.1039/C4DT03128H
Abstract

The previously reported monochelate iron complex with κ3 SNS thioamide pincer ligand, 2,6-bis(N-2,6-bis(diphenylmethyl)-4-isopropylphenyliminothiolate)pyridine (LDPM), [Fe(THF)2(κ3-LDPM)], gave novel complexes, [Fe(NHC)(κ3-LDPM)] and [Fe(NO)2(κ3-LDPM)], by substitution reactions with N-heterocyclic carbene (NHC) and NO molecules, respectively. The X-ray crystal structure of the [Fe(NHC)(κ3-LDPM)] complex revealed a unique square planar iron(II) complex, which was determined to be in an intermediate spin state (S = 1) in benzene from the Evans method. The [Fe(NO)2(κ3-LDPM)] complex was determined to have a trigonal bipyramidal geometry from X-ray analysis and was indicated to be diamagnetic from the 1H NMR spectrum. The ν(NO) stretching vibration of this complex showed two peaks at 1840 cm−1 and 1790 cm−1, and also the Fe–N–O bond angles were 168.9(2)° and 168.03(19)°. These findings suggest that the two coordinated NO molecules have neutral radical character, and they are antiferromagnetically coupled with the high-spin iron center.

Graphical abstract: Nitrosyl and carbene iron complexes bearing a κ3-SNS thioamide pincer type ligand