Showing papers by "Richard D. Adams published in 1997"
TL;DR: In this paper, the structure of NaCa3IrO6 (I) is solved by means of single crystal X-ray diffraction data analysis with the reliability factors for I of R = 0.032 and Rw = 0.,039; and the reliability factor for II of R < 0.024 and Rw ≥ 0.031.
Abstract: NaCa3IrO6 (I) and NaCa3RuO6 (II) crystallize with trigonal (rhombohedral) symmetry in the space group R3c, Z = 6, for Ia = 9.272(3) A, c = 11.214(1) A; for IIa = 9.244(3) A, c = 11.201(1) A. NaCa3IrO6 (I) and NaCa3RuO6 (II) are isotypic to compounds of the Sr4PtO6 structure type. The structures have been solved by means of single crystal X-ray diffraction data analysis with the reliability factors for I of R = 0.032 and Rw = 0.039; and the the reliability factors for II of R = 0.024 and Rw = 0.031. The structure consists of infinite chains of alternating face-sharing MO6 octahedra, where MIr or Ru, and NaO6 trigonal prisms. The chains are separated by the calcium cations.
Strukturen und Charakterisierung von zwei neuen Oxiden vom Sr4PtO6-Typ: NaCa3IrO6 und NaCa3RuO6
NaCa3IrO6 (I) und NaCa3RuO6 (II) kristallisieren mit trigonaler (rhomboedrischer) Symmetrie in der Raumgruppe R3c, Z = 6, I: a = 9,272(3) A, c = 11,214(1) A, II: a = 9,244(3) A, c = 11,201(1) A. I und II sind isotyp zu Verbindungen vom Sr4PtO6-Typ. Die Strukturen wurden mittels Rontgen-Einkristallstrukturanalyse gelost mit einem R-Wert von 0,032 und Rw = 0,039 fur I bzw. R = 0,024 und Rw = 0,031 fur II. Die Struktur besteht aus unendlichen Ketten von flachenverknupften MO6-Oktaedern mit MIr bzw. Ru und trigonalen Prismen von NaO6. Die Ketten sind getrennt durch Calcium-Kationen.
46 citations
TL;DR: The thiirane complexes W(CO)5(SCH2CH2), 1, W( CO)5 (cis-SCHMeCHMe), 2, and W(co-5(trans-sCHMeChMe), 3, have been prepared and characterized as mentioned in this paper.
30 citations
TL;DR: In this article, a macrocyclization mechanism consisting of a metal-induced ring-opening cyclooligomerization of three, four, and five molecules of 3,3-DMT, respectively, is proposed.
15 citations
TL;DR: The catalytic ring opening of β-propiothiolactone, 1, and 3,3-dimethyl-β-propsynthetic acid (BP-AOA), 2, by Re2(CO)9(NCMe), Mn2( CO)9 (NCMe) and Mn2 (CO)10 has been investigated as mentioned in this paper.
13 citations
TL;DR: The reaction of Fe2(CO)6(μ-S2),1 withbis(dibenzylideneacetone)-palladium, Pd(dba)2, in the presence of 2,2′-bipyridine yielded the new compound Fe2 (CO) 6(μ 3-S)2Pd(bipy),2 in good yield (66%) as mentioned in this paper.
Abstract: The reaction of Fe2(CO)6(μ-S2),1 withbis(dibenzylideneacetone)-palladium, Pd(dba)2, in the presence of 2,2′-bipyridine yielded the new compound Fe2(CO)6(μ 3-S)2Pd(bipy),2 in good yield (66%). Compound2 was characterized by IR,1H NMR and single-crystal X-ray diffraction analyses. Compound2 contains a Pd(bipy) group that has been inserted into the S-S bond of1. Crystal data for2: space group P21/n,a=10.019(2) A,b=25.414(5) A,c=7.714(2) A,β=90.26(2)°,Z=4, 1436 reflections,R=0.023.
11 citations
TL;DR: In this paper, three new polyselenoether macrocycles were derived from DMSe, including 3,3-dimethylselenatane, 3,7-tetramethyl, 1,5-diselenacyclohexadecane and 1,9-hexamethyl.
10 citations
TL;DR: In this paper, a single crystal X-ray diffraction analysis was performed to characterize compounds 5a and 6 of the anion [Pt3Ru6(CO)21(μ3-H)(μ-H)2]−, which is a PPh3 derivative of the parent 1 that also contains the layer segregated stacking of Ru3 and Pt3 triangles.
Abstract: The reactions of [Pt3Ru6(CO)21(μ-H)3(μ3-H)] (1) with PMe3 and PPh3 have produced the salts [Pt(PR3)3H]-[Pt3Ru6(CO)21(μ3-H)(μ-H)2], 5a and 5d, R = Me and Ph in the yields 9% and 22%, respectively. By contrast the reaction of 1 with PPh3 in the presence of Me3NO has yielded the phosphane-substituted derivative [Pt3Ru6(CO)20(PPh3)μ-H)3(μ3-H)] }(6) in 22% yield. Compounds 5a and 6 were characterized by single crystal X-ray diffraction analysis. Compounds 5a and 5d are salts of the anion [Pt3Ru6(CO)21(μ3-H)(μ-H)2]−. The anion contains a layer segregated Ru3Pt3Ru3 structure similar to that of 1 with two bridging hydride ligands on one Ru3 triangle and one semi-triply bridging hydride ligand on the other. The cation [Pt(PR3)3H]+ was evidently formed by the abstraction of platinum from other molecules of 1. Compound 6 is a PPh3 derivative of the parent 1 that also contains the layer segregated stacking of Ru3 and Pt3 triangles. The PPh3 ligand is coordinated to one of the ruthenium atoms in an axial position.
9 citations
TL;DR: In this paper, two new compounds, Cu4(AsO4)2O (1) and Ba2Cu7As6O24 (2), were obtained from a mixture of CuO and As2O5 · xH2O heated to 1090°C for 72 h in a BaCO3 flux.
Abstract: Two new compounds Cu4(AsO4)2O (1) and Ba2Cu7As6O24 (2) were obtained from a mixture of CuO and As2O5 · xH2O heated to 1090°C for 72 h in a BaCO3 flux. Compound 1 was obtained as dark green crystals, belonging to the orthorhombic crystal system. Compound 2 was obtained as light gray to colorless crystals belonging to the triclinic crystal system. The structure of 1 contains two copper ions with distorted trigonal bipyramidal geometries and a third with a distorted square pyramidal geometry. One ‚oxide’ ion is surrounded by four copper ions in a distorted tetrahedral arrangement. Compounds 2 consists of two chains with alternating units of trigonal bipyramidal CuO5 and square planar CuO4 units, with the oxygen atoms derived from the AsO4 groups. Magnetic susceptibility measurements of 1 and 2 both show effective magnetic moments, μeff1.90–1.95 B.M./Cu at 25°C, which is consistent with Cu2+ ions having one unpaired electron. Significant antiferromagnetic coupling was revealed by variable temperature measurements. At very low temperatures (15–25 K) samples of both 1 and 2 undergo a transition to a weak ferromagnetic state.
7 citations
4 citations
TL;DR: In this paper, the reaction of Ru3(CO)12 with MeO2C(H)C=C=H)CO2 Me has yielded two isomeric productsanti-Ru2(CO), 6[μ-η3-ε1-MeO2c(H),CCC(H)]CO2Me],1 in 70% yield andsyn-Ru 2,CO,6[μ −ε3 −δ 1 −1 −1−MeO 2C,H)Co2Me]2 in 5% yield.
Abstract: The reaction of Ru3(CO)12 with MeO2C(H)C=C=C(H)CO2 Me has yielded two isomeric productsanti-Ru2(CO)6[μ-η3-η1-MeO2C(H)CCC(H)CO2Me],1 in 70% yield andsyn-Ru2(CO)6[μ-η3-η1-MeO2C(H)CCC(H)CO2Me],2 in 5% yield. Both compounds were characterized by single crystal X-ray diffraction analysis. Both products are diruthenium complexes with bridging di(carboxylate)allene ligands in which the oxygen atom of the carbonyl group of one of the carboxylate groupings is coordinated to one of the metal atoms. Compound1 isomerizes partially to2 at 68°C. Crystal Data for1: space group=P21/n,a=11.131(1) A,b=10.228(2) A,c=15.978(2) A,β=102.01(1)°,Z=4, 1653 reflections,R=0.025; for2: space group=P\(\bar 1\),a=9.340(1) A,b=14.925(4) A,c=6.778(2) A,α=99-02(2)°,β=104 62(2)°,γ=94.58(2)°,Z=2, 1857 reflections,R=0.027.
3 citations
TL;DR: The barium copper titanate compound Ba8Cu2Ti22O54 was obtained in a crystalline form by heating a mixture of BaCO3, CuO, and TiO2 at 1380°C for 48 hours as discussed by the authors.