title: Synthesis and characterization of new five-coordinate platinum nitrosyl derivatives: density functional theory study of their electronic structure.
abstract: The neutral, five-coordinate platinum nitrosyl compounds [Pt(C(6)F(5))(3)(L)(NO)] (2) [L=CNtBu (2 a), NC(5)H(4)Me-4 (2 b), PPhMe(2) (2 c), PPh(3) (2 d) and tht (2 e)] have been prepared by the reaction of [NBu(4)][Pt(C(6)F(5))(3)(L)] (1) with NOClO(4) in CH(2)Cl(2). The ionic compound [N(PPh(3))(2)][Pt(C(6)F(5))(4)(NO)] (4) has been prepared in a similar way starting from the homoleptic species [N(PPh(3))(2)](2)[Pt(C(6)F(5))(4)] (3). Compounds 2 and 4 are all diamagnetic with [PtNO](8) electronic configuration and show nu(NO) stretching frequencies at around 1800 cm(-1). The crystal and molecular structures of 2 c and 4 have been established by X-ray diffraction methods. The coordination environment for the Pt center in both compounds can be described as square pyramidal (SPY-5). Bent nitrosyl coordination is observed in both cases with Pt-N-O angles of 120.1(6) and 130.2(7) degrees for 2 c and 4, respectively. The bonding mechanism of the nitrosyl ligand coordinated to various model [Pt(II)R(4)](2-) (R=H, Me, Cl, CN, C(6)F(5) or C(6)Cl(5)) and [Pt(C(6)F(5))(3)(L)](-) (L=CNMe, PH(3)) systems has been studied by density functional calculations at the B3LYP level of theory, using the SDD basis set. The R(4)Pt-NO and (C(6)F(5))(3)(L)Pt-NO interactions generally involve two components: i) a direct Pt-NO bonding interaction and ii) multicenter-bonding interactions between the N atom of the NO ligand and the donor atoms of the R and L ligands. Moreover, with the more complex R groups, C(6)F(5) or C(6)Cl(5), a third component has been found to arise, which involves multicenter electrostatic interactions between the positively charged NO ligand and the negatively charged halo-substituents in the ortho-position of the C(6)X(5) groups (X=F, Cl). The contribution of each component to the Pt-NO bonding in R(4)Pt-NO and (C(6)F(5))(3)(L)Pt-NO compounds seems to be modulated by the electronic and steric effects of the R and L ligands.
authors.affiliation: Departamento de Química Inorgánica Instituto de Ciencia de Materiales de Aragón Facultad de Ciencias, Universidad de Zaragoza-C.S.I.C. Pza. S. Francisco s/n, 50009 Zaragoza, Spain.
authors.forename: Irene
authors.initials: I
authors.lastname: Ara
authors.forename: Juan
authors.initials: J
authors.lastname: Forniés
authors.forename: María Angeles
authors.initials: MA
authors.lastname: García-Monforte
authors.forename: Babil
authors.initials: B
authors.lastname: Menjón
authors.forename: Rosa María
authors.initials: RM
authors.lastname: Sanz-Carrillo
authors.forename: Milagros
authors.initials: M
authors.lastname: Tomás
authors.forename: Athanassios C
authors.initials: AC
authors.lastname: Tsipis
authors.forename: Constantinos A
authors.initials: CA
authors.lastname: Tsipis