Methane Crystal structure

M. Prager, W. Press, B. Asmussen J. Combet (2002). J. Chem. Phys., 117, 5821-5826. Phase III of methane crystal structure and rotational tunneling. 

Oxetane, 3,3-bis(trimethylaminomethyl)-methane sulfonate X-ray crystal structure, 7, 365 Oxetane, 3-bromo-synthesis, 7, 390 Oxetane, 2-t-butyl-3-methyl-synthesis, 7, 399 Oxetane, 2-chloro-reactions, 7, 390 Oxetane, 3-chloro-synthesis, 7, 390... 

Ermler U, W Grabarse, S Shima, M Goubeaud, RK Thauer (1997) Crystal structure of methyl-coenzyme M reductase the key enzyme of biological methane formation. Science 278 1457-1462. 

The characterization and crystal structure of the dimer [Pt2( -dppm)3] (dppm = bis(diphenyl-phosphino)methane), first reported as a deep red complex in 1978, was described by Manojlovic-Muir et al. in 1986.11 The structure, the first of its type, is made up of two parallel and almost eclipsed trigonal-planar platinum moieties bridged by three diphosphine ligands. The Pf Pt separation is 3.0225(3) A, too long to be considered a bond.11 [Pt2(//-dppm)3] catalyzes the hydrogenation/reduction of carbon dioxide with dimethylamine to give dimethylformamide12 (Equation (1)) and the reverse reaction.13... 

Lieberman, R.L. and Rosenzweig, A.C. (2005) Crystal structure of a membrane-bound metalloenzyme that catalyses the biological oxidation of methane, Nature, 434, 177-182. 

Various X-ray crystal structures of metal-ligand complexes provided evidence of the geometry of the complexes in the solid state, even though the structure of these complexes may differ in solution. The hrst crystal structure of a bis(oxazoline)-metal complex was determined in 1994 by Brown and co-workers. " This group crystallized and elucidated the structure of V,V-bis-[2-((45)-(methyl)-l,3-oxazoli-nyl)]methane-bi(ri ethene)rhodium(I), 18a, as depicted in Figure 9.3. The key features of this crystal structure include the C2-axis of symmetry, the axial positions of the methyl groups and the orientation of the ethene molecules, orthogonal to the complexation square plane. In 1995, Woodward and co-workers were able to crystallize and determine the structure of benzylbis(oxazoline) with ruthenium... 

Bidentate diphosphines, such as bis(diphenylphosphino)methane (dppm) [242— 244], l,2-bis(diphenylphosphino)ethane (dppe) [245], l,2-bis(hydroxymethylpho-sphinojethane (hmpe) [246], l,2-bis(dicydohexyphosphine)ethane (dcype) [247] or bis(diphenylphosphino)isopropane (dppip) [248] build structures of stoichiometry [Au2(P P)2]2+ such as those shown in Figure 2.45. The crystal structure of [Au2(dmpe)2]X2-nH20 (dmpe = l,2-bis(dimethylphosphino)ethane X = Cl, n = 2 Br, = 1.5) consist of polymeric chains anion/water molecule/cation/anion/cat-ion/anion/water molecule [249]. 

Figure 16-28 Proposed mechanism of action of the methane-forming coenzyme M reductase. Based on the crystal structure.

A completely similar reaction occurs when Ru2(CO)6(R-Pyca R R2 ) (R-Pyca R R2 = 6-R NC5H3-2-C(R2) = NR with R = alkyl or aryl Rl = H, Me and R2 = H, Me) is reacted with excess pyridinimine.164 The facile reaction leads to the formation of Ru2(CO)5(APM) (APM — bis(/i-t-butylamino)(2-pyridyl)methane-N) (ref. 162, footnote). (The crystal structure of this compound shows two C—C-coupled pyridin-2-imines which bridge a non-bonding Ru2 metal pair. The... 

Reaction of the bis(diphenylphosphino)methane (dppm) complex PdPt-(yi-dppm)2Cl2 (132) with carbonylate anions affords several tri- and tetranuclear clusters. Reactions are outlined in Scheme 7. Treatment of 132 with 2 mol equivalents of [Fe(CO)3(NO)] (796,797), [Co(CO)4] (196,198), or [Mn(CO)5] (196,197) results in the tetranuclear spiked triangular clusters 133,134, or 135. Crystal structures on the dipalladium analogues of 134 and 135 have been reported (797,799). Grossel et al. (136) and Braunstein et al. (200) have independently reported that reaction of 132 with 1 mol equivalent of [Fe(CO)4]2 at ambient temperatures leads to an inseparable 1 1 mixture... 

Although polymorphism in plastic crystals is less frequent than in liquid crystals, it does exist. Tetrakis(methylmercapto)methane, C(SCH3)4, for example, has four crystal modifications of which the three high temperature forms have a high degree of plasticity 100). Also, it has been observed that plastic crystals are frequently mutually soluble 16b), a consequence of the less restrictive crystal structures. Phase separation of these solutions occurs often on transition to the fully ordered crystal, giving rise to quite complicated phase diagrams102). 

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