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Bryan M. Gatehouse

Bio: Bryan M. Gatehouse is an academic researcher from Monash University, Clayton campus. The author has contributed to research in topics: Crystal structure & Denticity. The author has an hindex of 21, co-authored 92 publications receiving 1346 citations.


Papers
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TL;DR: In this article, the crystal structures of the isomorphous salts MI6[Mo7O24],4H2O (M = NH4 or K) have been refined by three-dimensional X-ray diffraction methods.
Abstract: The crystal structures of the isomorphous salts MI6[Mo7O24],4H2O (M = NH4 or K) have been refined by three-dimensional X-ray diffraction methods. Unit cell dimensions of these monoclinic compounds, space group P21/C with Z= 4, are, ammonium salt: a= 8·3934 ± 0·0008, b= 36·1703 ± 0·0045, c= 10·4715 ± 0·0011 A, β= 115·958°± 0·008°; and potassium salt: a= 8·15 ± 0·02, b= 35·68 ± 0·1, c= 10·30 ± 0·02 A, β= 115·2°± 02°.By use of multiple Weissenberg patterns, 8197 intensity data (Mo-Kα radiation) for the ammonium compound and 2178 (Cu-Kα radiation) for the potassium compound were estimated visually and used to test and refine Lindqvist's proposed structure in the space group P21/c. Lindqvist's structure was confirmed and the full matrix least-squares isotropic refinement led to R 0·076 (ammonium) 0·120 (potassium), with direct unambiguous location of the cations and water molecules in the potassium compound.

94 citations

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TL;DR: C 24 H 20 CoN 4 O 2 cristallise dans P2 1 /n avec Z=4; affinement jusqu'a R=0,062.
Abstract: C 24 H 20 CoN 4 O 2 cristallise dans P2 1 /n avec Z=4; affinement jusqu'a R=0,062. Coordination pyramide carree deformee

78 citations

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TL;DR: In this article, a linear relation is obtained between 2J(1H-199Hg) and protonation constants for N, where L = N-alkylimidazoles, and the relation is similar to that obtained previously for pyridines.
Abstract: Complexes [MeHgL]N03 (L = 4,4’,4’’-triethyL2,2':6’,2”-terpyridyl (Et3terpy), terpy, bis(2-pyridy1)methanes ((py)CH2's), (py)2CMe2, (py)2CEt2, tris(2-pyridyl)methane, several N-alkylimidazoles, N-(2-pyridyl)imidazole, and N-methyl-2-(2-pyridy1)imidazoles) are obtained from addition reactions in acetone. Proton magnetic resonance spectroscopy is used to deduce coordination behavior of potential uni- or polydentate ligands in methanol, indicating that Et3terpy, terpy, (py)2CH2's, and N-methyl-2-(2-pyridyl)imidazoles act as bidentates to give three-coordinate mercury, but (py)2CR2 (R = Me, Et) are present as unidentates. A linear relation is obtained between 2J(1H-199Hg) for [MeHgL]+ and protonation constants for L, where L = N-alkylimidazoles, and the relation is similar to that obtained previously for L = pyridines. The ambidentate ligand N-(2-pyridyl)imidazole binds to mercury via the imidazole ring. Crystalline [MeHg((py)2CH2)]N03 has (py)CH2 present as a bidentate ligand with “T-shape” coordination geometry based on a dominant C-Hg-N moiety [Hg-N = 2.16(1) A, C-Hg-N = 172 (1) and a weaker Hg-N’ bond [2.75(2) A]. Crystalline [MeHg(Et3terpy)]N03 has Et3terpy present as a tridentate ligand with MeHg(II) bonded strongly to the central nitrogen [2.26(2) A, C-Hg-N = 171(1) and weakly to the terminal nitrogens [2.51(2), 2.61(2) A]. Syntheses of new ligands containing pyridyl and N-methylimidazolyl donor groups are described.

64 citations

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TL;DR: In this paper, the erbium complex has been shown to be monomeric with eight coordination of the metal and a trigonal bipyramidal arrangement of the centre (Cen) of the N-N bonds of three η2-3,5-diphenylpyrazolate groups.
Abstract: From reaction of lanthanoid metals with bis ( pentafluorophenyl )mercury and 3,5-diphenylpyrazole (HPh2pz) in 1,2-dimethoxyethane ( dme ) and treatment of the products with triphenylphosphine oxide, the complexes [ Ln (η2-Ph2pz)3(OPPh3)2].( dme )n ( Ln = Er or Nd , n = 1; Ln = La, n = 0.6) have been isolated. An X-ray crystal structure shows that the erbium complex [monoclinic, space group C2, a 22.08(3), b 14.30(1), c 13.37(1) Ǻ, β 124.09(7)°, Z 2 2730 'observed' data refined to R 0.046] is monomeric , with eight coordination of the metal. There is a trigonal bipyramidal arrangement of the centre ( Cen ) of the N-N bonds of three η2-3,5-diphenylpyrazolate groups ( ΣCen-Er-Cen 360°; ( Er -N) 2.344 Ǻ) and the oxygens of two equivalent trans triphenylphosphine oxide ligands [O- Er -O 176(1)°; Er -O 2.207(9)Ǻ]. Unit cell data indicate that the neodymium analogue [monoclinic, space group C2, a 23.01(3), b 14.94(2), c 13.82(2) Ǻ, β 123.65(8)°] is isostructural with the erbium complex. An analogous reaction of lanthanum or neodymium metal, Hg(C6F5)2, and HPh2pz in tetrahydrofuran ( thf ) gives [ Ln (η2-Ph2pz)3( thf )3]. thf ( Ln = La or Nd ). The X-ray crystal structure of the neodymium complex [orthorhombic, space group P212121, a 14.009(9), b 16.280(8), c 22.640(16)Ǻ, Z 4, 2967 'observed' data refined to R 0.046 reveals a nine-coordinate monomer with three η2-Ph2pz ligands [ Nd -N 2.420(10)-2.524(8)Ǻ] and three thf ligands [ Nd -O 2.497(8)-2.587(8)Ǻ]. There is a trigonal prismatic arrangement of the centres of the N-N bonds and the oxygen donor atoms.

56 citations


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TL;DR: In this Review, highlights of a number of selected syntheses are discussed, demonstrating the enormous power of these processes in the art of total synthesis and underscore their future potential in chemical synthesis.
Abstract: In studying the evolution of organic chemistry and grasping its essence, one comes quickly to the conclusion that no other type of reaction plays as large a role in shaping this domain of science than carbon-carbon bond-forming reactions. The Grignard, Diels-Alder, and Wittig reactions are but three prominent examples of such processes, and are among those which have undeniably exercised decisive roles in the last century in the emergence of chemical synthesis as we know it today. In the last quarter of the 20th century, a new family of carbon-carbon bond-forming reactions based on transition-metal catalysts evolved as powerful tools in synthesis. Among them, the palladium-catalyzed cross-coupling reactions are the most prominent. In this Review, highlights of a number of selected syntheses are discussed. The examples chosen demonstrate the enormous power of these processes in the art of total synthesis and underscore their future potential in chemical synthesis.

2,268 citations

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TL;DR: In this paper, the preparation of a colloidal colloidal by un procede sol gel is described, and a procedure for determination des proprietes electriques et electrochimiques is described.

2,040 citations

Journal ArticleDOI
TL;DR: The power of cascade reactions in total synthesis is illustrated in the construction of complex molecules and underscore their future potential in chemical synthesis.
Abstract: The design and implementation of cascade reactions is a challenging facet of organic chemistry, yet one that can impart striking novelty, elegance, and efficiency to synthetic strategies. The application of cascade reactions to natural products synthesis represents a particularly demanding task, but the results can be both stunning and instructive. This Review highlights selected examples of cascade reactions in total synthesis, with particular emphasis on recent applications therein. The examples discussed herein illustrate the power of these processes in the construction of complex molecules and underscore their future potential in chemical synthesis.

1,762 citations

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TL;DR: The Diels-Alder reaction has both enabled and shaped the art and science of total synthesis over the last few decades to an extent which has yet to be eclipsed by any other transformation in the current synthetic repertoire as mentioned in this paper.
Abstract: The Diels-Alder reaction has both enabled and shaped the art and science of total synthesis over the last few decades to an extent which, arguably, has yet to be eclipsed by any other transformation in the current synthetic repertoire. With myriad applications of this magnificent pericyclic reaction, often as a crucial element in elegant and programmed cascade sequences facilitating complex molecule construction, the Diels-Alder cycloaddition has afforded numerous and unparalleled solutions to a diverse range of synthetic puzzles provided by nature in the form of natural products. In celebration of the 100th anniversary of Alder's birth, selected examples of the awesome power of the reaction he helped to discover are discussed in this review in the context of total synthesis to illustrate its overall versatility and underscore its vast potential which has yet to be fully realized.

1,427 citations