Showing papers by "George M. Sheldrick published in 1977"
TL;DR: A crystallographic study of [(Ph3P)2Pt(N2O2)] showed that the two NO groups are coupled via the nitrogen atoms, forming a cis-hyponitrite ligand, which bonds to platinum through the oxygen atoms to give a [graphic omitted] ring.
Abstract: A crystallographic study of [(Ph3P)2Pt(N2O2)] shows that the two NO groups are coupled via the nitrogen atoms, forming a cis-hyponitrite ligand, which bonds to platinum through the oxygen atoms to give a [graphic omitted] ring.
38 citations
TL;DR: The X-ray structure determination of [Ru4(CO)12(C2Ph2] confirms the previously proposed closo-Ru4C2 unit with the alkyne capping a butterfly arrangement of the four ruthenium atoms as discussed by the authors.
Abstract: The X-ray structure determination of [Ru4(CO)12(C2Ph2)] confirms the previously proposed closo-Ru4C2 unit with the alkyne capping a butterfly arrangement of the four ruthenium atoms. Crystals are monoclinic, space group P21/c, Z= 4, a= 9.69(1), b= 16.88(2), c= 17.13(2)A, β= 90.67(5)°; R 0.056 for 2 929 independent reflections. Variable-temperature 13C n.m.r. spectroscopy has enabled the activation energy and entropy to be measured for the mutual exchange of three carbonyl groups attached to one ruthenium, and also indicates that no exchange of carbonyls between different rutheniums occurs at <373 K.
36 citations
TL;DR: In this paper, the preparation and isolation of (I), (II), (III), (IV), and (V) are described, where pip = piper-idine and the gold atoms forming a loose square cluster.
Abstract: The preparation and isolation of (I)[Au(pip)Cl], (II)[AuCl(pip)2], and (III)[Au(pip)2][PF6](where pip = piper-idine) are described. The X-ray structure of (I) is reported : it consists of linear [(pip)AuCl] molecules arranged in tetramers, the gold atoms forming a loose square cluster. The structure was determined by the heavy-atom method from 1089 unique reflections measured by diffractomer and refined by least-squares techniques to R 0.064. Crystals are tetragonal, a= 12.474(20), c= 9.694(10)A, Z= 8.
34 citations
31 citations
TL;DR: In this paper, the results of X-ray diffraction studies have established the molecular structure of the title compound as involving an unexpected [3.2.1]cyclooctadienylium ligand; the implications of this in terms of chemical reactivity are described.
16 citations
TL;DR: In this article, the preparation and isolation of (I), (II), (III), (IV), and (V) are described, where pip = piper-idine and the gold atoms forming a loose square cluster.
Abstract: The preparation and isolation of (I)[Au(pip)Cl], (II)[AuCl(pip)2], and (III)[Au(pip)2][PF6](where pip = piper-idine) are described. The X-ray structure of (I) is reported : it consists of linear [(pip)AuCl] molecules arranged in tetramers, the gold atoms forming a loose square cluster. The structure was determined by the heavy-atom method from 1089 unique reflections measured by diffractomer and refined by least-squares techniques to R 0.064. Crystals are tetragonal, a= 12.474(20), c= 9.694(10)A, Z= 8.
4 citations
3 citations
TL;DR: In this paper, the structure (E)-3,6-dihydroxy-2,methyl-1,4-benzoquinone 4-methoxyimine N-oxide was confirmed by X-ray analysis.
Abstract: Treatment of 1,3,6-trihydroxy-2-methyl-4-nitrobenzene (protonated 1) with diazomethane produces not only the expected 1-methoxy derivative but also a substantial amount of an isomer with the novel structure (E)-3,6-dihydroxy-2-methyl-1,4-benzoquinone 4-methoxyimine N-oxide (3); the structure of (3) is confirmed by X-ray analysis.
1 citations
1 citations
TL;DR: In this paper, the structure (E)-3,6-dihydroxy-2,methyl-1,4-benzoquinone 4-methoxyimine N-oxide was confirmed by X-ray analysis.
Abstract: Treatment of 1,3,6-trihydroxy-2-methyl-4-nitrobenzene (protonated 1) with diazomethane produces not only the expected 1-methoxy derivative but also a substantial amount of an isomer with the novel structure (E)-3,6-dihydroxy-2-methyl-1,4-benzoquinone 4-methoxyimine N-oxide (3); the structure of (3) is confirmed by X-ray analysis.
TL;DR: The complex [Os6(CO)13] reacts with methanolic potassium hydroxide to produce [Os5(CO]15]2, which, upon acidification, gives [HOs5/CO)15] and [H2/CO].
Abstract: The complex [Os6(CO)13] reacts with methanolic potassium hydroxide to produce [Os5(CO)15]2– which, upon acidification, gives [HOs5(CO)15]– and [H2Os5(CO)15]; single crystal X-ray diffraction and 13C n.m.r. studies show the presence, within the anionic pentaosmium clusters, of trigonal bipyramidal metal arrangements.