Spectroscopic study and x-ray structure of bis(N-methylimidazole)bis(2,4,6, trichlorophenolato)cobalt(II)

✍ Scribed by Marina Biagini Cingi; Anna Maria Manotti Lanfredi; Antonio Tiripicchio; Cornelis G. Van Kralingen; Jan Reedijk

• Publisher: Elsevier Science
• Year: 1980
• Tongue: English
• Weight: 506 KB
• Volume: 39
• Category: Article
• ISSN: 0020-1693
• DOI: 10.1016/s0020-1693(00)93665-x

✦ Synopsis

The preparation, spectroscopic study and X-ray structure of the mixed-valence compound Pt(NMlz)4-PtC16 are described; NMlz stands for N-methylimidazole.

The crystal and molecular structure has been determined by a single crystal X-ray analysis using three-dimensional diffractometer data. The compound crystallizes in the triclinic system, with four formula units in the unit cell, space group Fi and lattice parameters a = 1.5.228( 11), b = 17.855(12), c = 11.177(g) & (Y = 91.98(6), /3 = 106.94(6), y = 115.76( 7)". The structure was solved and refined using the heavy-atom method and subsequent least-squares techniques. Refinements using 2335 observed reflections (MO-Ka radiation) led to final values for R and R, of 0.077and 0.075 respectively.

The Pt(lI) ions are surrounded in a square-planar geometry by four NMlz ligands (Pt-N = 1.986-2.012(14) A and N-P&N = 92.6(6)"). Pt(lV) is octahedrally coordinated by the six C% ions (P&Cl = 2.313-2.323( 6) and CI-Pt&Cl = 88.3389.9(2/O). In addition there is an interaction between the Pt(NMlz):' ions and the

PtClf ions (with Pt. . .C'l = 3.538(J) A and Pt(l1). . . Cl-Pt(lV) = 144.1') and Pt(l1). Pt(lV) = 5.588 A), resulting in a chain-type behaviour along the taxis. Optical, infrared and far-infrared spectra agree with this structure. No clear intervalence charge-transfer absorption could be detected which might be related to the relatively long Pt(l1). . .Pt(IV) distance in this compound.