ISSN:
1572-8862
Keywords:
Platinum
;
electronic spectra
;
luminescence
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Abstract A new organometallic cluster [Pt4(μ2-dpam)3(μ2-CO)3(η1-dpam)] X2 (X=CF3CO 2 - ; 4a) was prepared from a reaction between Pt(dpam)(CF3CO2)2 and CO in a methanol (water mixture). The PF 6 - salt 4b is obtained from an anion exchange with NH4PF6 in methanol. Dark red crystals suitable for X-ray crystallography (X=PF 6 - ) revealed the commonly encountered butterfly structure for a 58-electron Pt cluster (angle between the two Pt3 planes =95.36(8)°, nonbonding Pt...Pt distance =3.094(1) Å). The structure consists of two edge sharing Pt3 triangles, a small one 'Pt3(μ2-dpam) 3 2+ and a larger one “Pt3(μ2-CO)3(L)3” where L=As group. The Extended Huckel Molecular Orbital calculations (EHMO) have been rationalized from interactions of two L and PtL 2 2+ fragments onto the planar triangular Pt3(μ2-CO)3L3 cluster (L = AsH3). The compound is luminescent at 77 K with a structureless band located at 690 nm (τe=3.2 ±0.2μs). Finally, the 1H NMR spectra are interpreted, particularly with respect to fluxionality and presence of two isomers. X-ray data for 4b: orthorhombic, C c2a, a=26.320(9), b=27.613(6), c=28.891(4) Å, V=20998(9) Å3, Z=4, D(calc.)=1.925 Mg/m3.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1021942100115
Permalink
