Evidence for intrinsic electrical conduction in the linear metal-chain semiconductor bis(1,2-benzoquinonedioximato)platinum(II), Pt(bqd)2

The four-electrode dc conductivity of single crystals of the linear metal-chain compound bis(1,2-benzoquinonedioximato)platinum(II), Pt(bqd)₂, measured parallel to the long axis of the crystals, reveals ohmic behavior over the temperature range 77–550°K, and averages to $\text{σ}\text{= 3.3 × 10}{}^{\mathrm{?3}}\text{Ω}{}^{\mathrm{?1}}\text{cm}{}^{\mathrm{?1}}$ at room temperature. Unlike the well-characterized Magnus' Green Salt (MGS), Pt(NH₃)₄PtCl₄ ($\text{σ}\text{= 5.5 × 10}{}^{\mathrm{?4}}\text{Ω}{}^{\mathrm{?1}}\text{cm}{}^{\mathrm{?1}}\text{)}$, the present compound is found to be an intrinsic, small band gap semiconductor. The PtPt distance of 3.180 Å, the shortest yet observed in Pt(II) glyoximates, was determined by powder X-ray diffraction. The small band gap is related to the unusually high conductivity of Pt(bqd)₂, which is most reasonably interpreted in terms of this short PtPt separation. Preliminary results of polarized single crystal reflectance spectra demonstrating the anisotropic behavior of this compound are presented.     

Structure and resonance raman spectrum of the linear metal-chain compound bis(1,2-benzoquinonedioximato)-palladium triiodide,Pd(bqd)2I0.5 or Pd(bqd)2(I3)0.17

Struktur und Resonanz-Raman-Spektrum der Linear-Metallketten-Verbindung Bis(1,2-benzochinondioximato)palladiumtriiodid, Pd(bcd)₂I_0,5 bzw. Pd(bcd)₂(I₃)_0,17 Die Gitterstruktur der Titelverbindung wurde durch Beugung von Röntgenstrahlen am Einkristall unter Verwendung von MoKα-Strahlung auf einem Syntex P2₁, computerkontrollierten Diffraktometer ermittelt. Die kristallographischen Daten lauten: (PdC₁₂H₁₀N₄O₄)₂I, Molgew. = 888,19; tetragonale Raumgruppe P4/mcc (D_2h⁴); a = b = 15,977 Å, c = 6,371 Å; Z = 2; V = 1626,3 ų; D_rö = 1,81 g/cm³, D_beob = 1,79 g/cm³. Das Gitter kristallisiert mit ausgedehnten, geradlinigen Ketten von partiell oxidierten Pd-Ionen (dessen durchschnittliche Oxydationszahl rund +2,17 beträgt), d. h. die planaren Pd(bcd)₂-Komplexe sind entlang der c-Achse übereinander gestapelt mit einem regelmäßigen Pd—Pd-Abstand von 3,185 Å (1/2 c). Resonanz-Raman-Spektren der Verbindung (polykristalline Proben) wurden mit Hilfe einer Laser-Anregungsquelle (ν₀ = 5145 Å) bei Raumtemperatur aufgenommen. Die Spektren zeigen ausschließlich die charakteristischen Absorptionsbanden von unsymmetrischen I₃^?-Ionen an. Die Ergebnisse lassen darauf schließen, daß der Beitrag der Iodketten zu elektronischen Festkörperanisotropien in dieser Art von quasi-eindimensionalen Materialien vernachlässigbar klein ist.     

Crystal and molecular structure of bis(2-isotropyliminomethinylphenyl) telluride

Scientific-Research Institute of Physical and Organic Chemistry, Rostov State University. A. N. Nesmeyanov Institute of Heteroorganic Compounds, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 3, pp. 104–106, May–June, 1991.     

Crystal and molecular structure of trans-diiodobis-(1-methyl-5-nitroimidazole)platinum(II)

Summary A new platinum complex of 1-methyl-5-nitroimidazole has been obtained and characterized by elemental analysis, i.r. and n.m.r. spectroscopy. The structure of [PtI₂-(C₄ H₅N₃O₂)₂] has been determined by single-crystal X-ray diffraction. The crystals are triclinic: P1, a = 15.640(3), b = 12.617(2), c = 6.701(1) , = 102.77(5), = 101.15(5), = 100.71(5)°, V = 1228.6(3) ³, Z = 3, D_x = 2.851(6) Mg m^–3, (MoK ) = 0.71069 , = 12.85 mm^–, F(000) = 948, final R = 0.038 for 2859 reflections. The complex consists of monomeric PtI₂(1-methyl-5-nitroimidazole)₂ units. The coordination geometry is square-planar. The two 1-methyl-5-nitroimidazole ligands are trans coordinated to platinum.     

]Preparation and x-ray crystal structure of biss(diphenylphosphino)methanido platinum(II), [Pt(Ph2PCHPPh2)2]

[Pt(Ph₂PCHPPh₂)₂], the first homoleptic complex containing the chelated bis(diphenylphosphino)methanide ligand, has been synthesised by reaction of K₂[PtCl₄] and Ph₂PCH₂PPh₂ with KOH in ethanol, and characterised by ¹H and ³¹P NMR spectroscopy and X-ray crystallography.     

Mass spectral behavior of some homoleptic and mixed aryldichalcogenide bis(diphenylphosphino)ferrocenenickel(II), palladium(II), and platinum(II), and bis(diisopropylphosphino)ferrocenepalladium(II) complexes

The mass spectral behavior of a number of organometallic complexes containing the Group 10 metals Ni, Pd, and Pt, together with various thiolate ligands were studied. For Pd, two main types of complexes, differing by the substituents on the phosphorus atom were studied. Types I and II were substituted with bis(diphenylphosphino)ferrocene and bis(diisopropylphosphino)ferrocene ligands, respectively. The Ni complexes, except for one, and the Pd Type I complexes had no molecular radical cations (M(+.)) in their EI spectra. On the other hand, all the Pt complexes showed intense M(+.) ions in their EI spectra indicating that these complexes were more stable as radical cations than those of Ni and Pd. The FAB and MALDI spectra of all the complexes displayed intense quasi-molecular ions (MH(+)) and the fragmentations in both modes were similar. The MALDI spectra of several complexes displayed only M(+.) ions while one gave evidence of both MH(+) and M(+.) ions. Several Pd Type II complexes yielded intense M(+.) in their EI spectra.