Structure and bonding energy calculations of nitrosyl, thionitrosyl and selenonitrosyl complexes [(PNP)Ir(NX)]+ (X=O, S, Se): A DFT study

Ruthenium chalcogenonitrosyl and bridged nitrido complexes containing chelating sulfur and oxygen ligands

“…The Ru-N distances in 1 [1.753(4) Å] and 2 covalent double bonds, whereas the N-X bonding in the M(NX) (X = S, Se) analogues can be considered as donor-acceptor interactions between MuN and the X atom in the singlet state with two filled pπ orbitals (Scheme 3). 18,28,29 Also, it was suggested that the ratio of N-X (X = O, S, Se) stretching frequencies for M-NX complexes can provide insight into the M-NX bonding. For mer-[Ru(NX)Cl 3 (AsPh 3 ) 2 ], the ν(N-O) : ν(N-S) 27 ratio of 1.43 is similar to those of reported systems (1.40-1.47) 10,18,30 and significantly higher than the harmonic oscillator approximation (1.14) based on the reduced mass of NO and NS.…”

Synthesis and properties of anionic ruthenium thionitrosyl and selenonitrosyl complexes that contain tetraanionic 2-hydroxybenzamidobenzene ligands

“…28 However, it should also be noted here that this trend contradicts previous studies on complexes such as [Cr(NS)(OH 2 ) 5 ] 2+ , 29 [Os(NE)Cl 2 Tp] 7a or [Ru(NE)Cl 3 (AsPh 3 ) 2 ], 7d,12 in which the respective NO ligands appear to be better π-acceptors than the NS and NSe ligands, as well as the studies on [Ir(NE){N(CHCHP t Bu 2 ) 2 }][PF 6 ], 7c,13 where the π-acceptor ability of the NS ligand is lower than that of the NO and NSe ligands. 30 The aforementioned π-accepting nature of the NSe ligand in 5d was corroborated by the NPA charge distribution on the RuNSe moiety. The positive charge on the ruthenium atom is greater in 5d than in 6 and 4d [RuNO (6): 0.883; RuNS (4d): 0.980; RuNSe (5d): 1.006], while the negative charge on the nitrogen atom of the NE ligand is greater in 5d than in 6 and 4d [RuNO (6): 0.401; RuNS (4d): −0.348; RuNSe (5d): −0.409].…”