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81.
A gate to organokrypton chemistry: HKrCCH 总被引:1,自引:0,他引:1
Khriachtchev L Tanskanen H Cohen A Gerber RB Lundell J Pettersson M Kiljunen H Räsänen M 《Journal of the American Chemical Society》2003,125(23):6876-6877
An organic molecule containing krypton, HKrCCH, is reported. The preparation of HKrCCH includes 193-nm photolysis of H2C2/Kr solid mixtures at 8 K and subsequent thermal mobilization of hydrogen atoms at >/=30 K. The identification is based on infrared absorption spectroscopy and supported by ab initio calculations which show ionic and covalent contributions to the bonding. We believe that a series of similar organokrypton molecules can be prepared as computationally demonstrated for HKrC4H and HKrC3H3. These results feature a generally novel way for activating chemically the H-CC- group, which can find practical applications of the krypton catalysis. 相似文献
82.
Jouni Pursiainen Tapani A. Pakkanen Juhani Jääskeläinen 《Journal of organometallic chemistry》1985,290(1):85-98
A new ruthenium-rhodium mixed-metal cluster HRuRh3(CO)12 and its derivatives HRuRh3(CO)10(PPh3)2 and HRuCo3(CO)10(PPh3)2 have been synthesized and characterized. The following crystal and molecular structures are reported: HRuRh3(CO)12: monoclinic, space group P21/c, a 9.230(4), b 11.790(5), c 17.124(9) Å, β 91.29(4)°, Z = 4; HRuRh3(CO)10(PPh3)2·C6H14: triclinic, space group P, a 11.777(2), b 14.079(2), c 17.010(2) Å, α 86.99(1), β 76.91(1), γ 72.49(1)°, Z = 2; HRuCo3(CO)10(PPh3)2·CH2Cl2: triclinic, space group P, a 11.577(7), b 13.729(7), c 16.777(10) Å, α 81.39(4), β 77.84(5), γ 65.56°, Z = 2. The reaction between Rh(CO)4? and (Ru(CO)3Cl2)2 tetrahydrofuran followed by acid treatment yields HRuRh3(CO)12 in high yield. Its structural analysis was complicated by a 80–20% packing disorder. More detailed structural data were obtained from the fully ordered structure of HRuRh3(CO)10(PPh3)2, which is closely related to HRuCo3(CO)10(PPh3)2 and HFeCo3(CO)10(PPh3)2. The phosphines are axially coordinated. 相似文献
83.
Jan?KronqvistEmail author Andreas?Lundell Tapio?Westerlund 《Journal of Global Optimization》2016,64(2):249-272
A new deterministic algorithm for solving convex mixed-integer nonlinear programming (MINLP) problems is presented in this paper: The extended supporting hyperplane (ESH) algorithm uses supporting hyperplanes to generate a tight overestimated polyhedral set of the feasible set defined by linear and nonlinear constraints. A sequence of linear or quadratic integer-relaxed subproblems are first solved to rapidly generate a tight linear relaxation of the original MINLP problem. After an initial overestimated set has been obtained the algorithm solves a sequence of mixed-integer linear programming or mixed-integer quadratic programming subproblems and refines the overestimated set by generating more supporting hyperplanes in each iteration. Compared to the extended cutting plane algorithm ESH generates a tighter overestimated set and unlike outer approximation the generation point for the supporting hyperplanes is found by a simple line search procedure. In this paper it is proven that the ESH algorithm converges to a global optimum for convex MINLP problems. The ESH algorithm is implemented as the supporting hyperplane optimization toolkit (SHOT) solver, and an extensive numerical comparison of its performance against other state-of-the-art MINLP solvers is presented. 相似文献
84.
Juhani Nieminen 《Journal of Geometry》1989,34(1-2):146-151
A join space is an abstract model for partially ordered linear, spherical and projective geometries. A characterization for chordal graphs which are join spaces is given: a chordal graph is a join space if and only if it does not contain one of the two forbidden graphs as an induced subgraph. 相似文献
85.
W. Scott Graham Edgar A. R. Kemp A. Hoenig K. Schaffhäutl D. J. Carnegie A. Borar W. Mancbot F. Oberhauser G. E. A. Lundell H. B. Knowles W. L. Burdick M. Da Traube J. M. Hendel L. Storch W. Colet-Birch Erich Müller G. Wegelin Tamaki Nakazono G. T. Hough F. P. Treadwell J. S. Maclaurin und W. Donovan 《Fresenius' Journal of Analytical Chemistry》1927,70(12):452-462
Ohne Zusammenfassung 相似文献
86.
A. S. Russell C. A. Pierlé C. Ouelette E. C. Hatt P. F. Büchi O. Koblie A. Luyekx D. T. Ewing Mabel Wilson N. H. Furman I. C. Schoonover G. E. F. Lundell H. B. Knowles G. Kirsh W. F. Hillebrand Ellen Gleditsch C. W. Davis E. Körner Fr. Hecht O. Hönigschmid V. A. Matula S. Little H. Gräven H. Carvalho 《Analytical and bioanalytical chemistry》1933,93(9-10):373-399
87.
H. L. Campbell G. E. F. Lundell J. I. Hoffman H. A. Bright O. Kropf C. M. Johnson M. F. Garcia R. Kraiczek F. Sauerwald und A. Seuthe 《Fresenius' Journal of Analytical Chemistry》1935,101(7-8):287-290
Ohne Zusammenfassung 相似文献
88.
89.
J. M. Kolthoff F. G. Hills V. Lampe H. Beckurts F. Mayer L. Moser J. Singer G. Wynkoop A. Brukl O. Ruff E. Stephan M. Frommes M. Nießner W. F. Hillebrand G. E. F. Lundell Hellmut Fischer Grete Leopoldi A. Cissarz H. Schneiderhöhn E. Zintl J. Kassler H. B. Knowles H. V. Churchill R. W. Bridges M. F. Lee E. Dittler F. Kirnbauer B. E. Dixon Noyes Bray F. List W. Maxymowicz und F. Spindeck 《Fresenius' Journal of Analytical Chemistry》1933,93(7-8):285-307
Ohne Zusammenfassung 相似文献
90.