Nickel complexes of phosphine-appended benzannulated boron heterocycles

We report the synthesis and characterization of two diphosphine nickel complexes containing 9-borafluorene (PBFlu, 9-(diisopropylphosphino)phenyl-9-borafluorene) and 9,10-dihydroboranthrene (B 2 P 2 , 9,10-bis(2-(diisopropylphosphino)phenyl)-9,10-dihydroboranthrene) cores. Metalation of PBFlu and B 2 P 2 with Ni(PPh 3 ) 4 leads to the monometallic complexes (PBFlu)Ni(PPh 3 ) and (B 2 P 2 )Ni, respectively. Cyclic voltammetry studies show a reversible redox event at ∼0.1 V and a quasi-reversible event at ca. −3 V versus ferrocene/ferrocenium for (B 2 P 2 )Ni while (PBFlu)Ni(PPh 3 ) features no reversible redox events. Electronic structure calculations were performed to provide further insight into the bonding in these complexes

Reply to ``Comment on `On the inconsistency of the Bohm-Gadella theory with quantum mechanics'''

In this reply, we show that when we apply standard distribution theory to the Lippmann-Schwinger equation, the resulting spaces of test functions would comply with the Hardy axiom only if classic results of Paley and Wiener, of Gelfand and Shilov, and of the theory of ultradistributions were wrong. As well, we point out several differences between the ``standard method'' of constructing rigged Hilbert spaces in quantum mechanics and the method used in Time Asymmetric Quantum Theory.Comment: 13 page

Hydroamination reactions by metal triflates: Bronsted acid vs. metal catalysis?

Catalytic hydroamination reactions involving the addition of carboxamides (X = CO), carbamates (X = CO2) and sulfonamides (X = SO2) to unactivated CC bonds are briefly reviewed. Development in this field of catalytic research is briefly charted, followed by a discussion of possible mechanisms, including arguments to support the operation of both metal and Brønsted acid catalysis in these systems. Future developments in the area are summarised. © The Royal Society of Chemistry 2010.39511711175Müller, T.E., Hultzsch, K.C., Yus, M., Foubelo, F., Tada, M., (2008) Chem. Rev., 108, p. 3795Constable, D.J.C., Dunn, P.J., Hayler, J.D., Humphrey, G.R., Leazer, J.L., Linderman, R.J., Lorenz, K., Zhang, T.Y., (2007) Green Chem., 9, p. 411Ranu, B.C., Banerjee, S., (2007) Tetrahedron Lett., 48, p. 141. , For example, seeKumar, R., Chaudhary, P., Nimesh, S., Chandra, R., (2006) Green Chem., 8, p. 356Dzhemilev, U., Tolstikov, G., Khusnutdinov, R., (2009) Russ. J. Org. Chem., 45, p. 957Quinet, C., Jourdain, P., Hermans, C., Atest, A., Lucas, I., Marko, I.E., (2008) Tetrahedron, 64, p. 1077. , See for exampleHorrillo-Martinez, P., Hultzsch, K.C., Gil, A., Branchadell, V., (2007) Eur. J. Org. Chem., p. 3311Crimmin, M.R., Arrowsmith, M., Barrett, A.G.M., Casely, I.J., Hill, M.S., Procopiou, P.A., (2009) J. Am. Chem. Soc., 131, p. 9670Hong, S., Marks, T.J., (2004) Acc. Chem. Res., 37, p. 673Walsh, P.J., Baranger, A.M., Bergman, R.G., (1992) J. Am. Chem. Soc., 114, p. 1708Müller, C., Koch, R., Doye, S., (2008) Chem.-Eur. J., 14, p. 10430Beller, M., Trauthwein, H., Eichberger, M., Breindl, C., Herwig, J., Müller, T.E., Thiel, O.R., (1999) Chem.-Eur. J., 5, p. 1306Rodriguez-Zubiri, M., Anguille, S., Brunet, J.J., (2007) J. Mol. Catal. A: Chem., 271, p. 145Bäckvall, J.E., Åkermark, B., Ljunggren, S.O., (1979) J. Am. Chem. Soc., 101, p. 2411Hahn, C., (2004) Chem.-Eur. J., 10, p. 5888. , See for exampleMotta, A., Fragala, I.L., Marks, T.J., (2006) Organometallics, 25, p. 5533Tobisch, S., (2008) Chem.-Eur. J., 14, p. 8590Aillaud, I., Collin, J., Hannedouche, J., Schulz, E., (2007) Dalton Trans., p. 5105Qian, H., Widenhoefer, R.A., (2005) Org. Lett., 7, p. 2635Karshtedt, D., Bell, A.T., Tilley, T.D., (2005) J. Am. Chem. Soc., 127, p. 12640Zhang, J., Yang, C., He, C., (2006) J. Am. Chem. Soc., 128, p. 1798Brouwer, C., He, C., (2006) Angew. Chem., Int. Ed., 45, p. 1744Giner, X., Najera, C., (2008) Org. Lett., 10, p. 2919Taylor, J.G., Whittall, N., Hii, K.K., (2005) Chem. Commun., p. 5103Taylor, J.G., Whittall, N., Hii, K.K., (2006) Org. Lett., 8, p. 3561Dias, H.V.R., Wu, J., (2008) Eur. J. Inorg. Chem., p. 509. , For a discussion of ethylene complexes ofCu(i), Ag(i) and Au(i), seeMcBee, J.L., Bell, A.T., Tilley, T.D., (2008) J. Am. Chem. Soc., 130, p. 16562Cheng, X.J., Xia, Y.Z., Wei, H., Xu, B., Zhang, C.G., Li, Y.H., Qian, G.M., Li, W., (2008) Eur. J. Org. Chem., p. 1929Rosenfeld, D.C., Shekhar, S., Takemiya, A., Utsunomiya, M., Hartwig, J.F., (2006) Org. Lett., 8, p. 4179Li, Z., Zhang, J., Brouwer, C., Yang, C.-G., Reich, N.W., He, C., (2006) Org. Lett., 8, p. 4175Wabnitz, T.C., Yu, J.Q., Spencer, J.B., (2004) Chem.-Eur. J., 10, p. 484Taylor, J.G., (2008), PhD Thesis, Imperial College LondonHuang, J.M., Wong, C.M., Xu, F.X., Loh, T.P., (2007) Tetrahedron Lett., 48, p. 3375Michaux, J., Terrasson, V., Marque, S., Wehbe, J., Prim, D., Campagne, J.M., (2007) Eur. J. Org. Chem., p. 2601Motokura, K., Nakagiri, N., Mori, K., Mizugaki, T., Ebitani, K., Jitsukawa, K., Kaneda, K., (2006) Org. Lett., 8, p. 4617Yang, L., Xu, L.W., Xia, C.G., (2008) Tetrahedron Lett., 49, p. 2882Kovacs, G., Ujaque, G., Lledos, A., (2008) J. Am. Chem. Soc., 130, p. 853Dorta, R., Egli, P., Zurcher, F., Togni, A., (1997) J. Am. Chem. Soc., 119, p. 10857Hartwig, J.F., (2004) Pure Appl. Chem., 76, p. 507. , These were shown to proceed via allylpalladium(ii) intermediates, see, and references thereinJohns, A.M., Sakai, N., Ridder, A., Hartwig, J.F., (2006) J. Am. Chem. Soc., 128, p. 9306Zhang, Z., Lee, S.D., Widenhoefer, R.A., (2009) J. Am. Chem. Soc., 131, p. 5372Anastas, P., Warner, J., (1998) Green Chemistry: Theory and Practice, , Oxford University Press, New Yor

The rigged Hilbert space approach to the Lippmann-Schwinger equation. Part I

We exemplify the way the rigged Hilbert space deals with the Lippmann-Schwinger equation by way of the spherical shell potential. We explicitly construct the Lippmann-Schwinger bras and kets along with their energy representation, their time evolution and the rigged Hilbert spaces to which they belong. It will be concluded that the natural setting for the solutions of the Lippmann-Schwinger equation--and therefore for scattering theory--is the rigged Hilbert space rather than just the Hilbert space.Comment: 34 pages, 1 figur

Challenges for Superstring Cosmology

We consider whether current notions about superstring theory below the Planck scale are compatible with cosmology. We find that the anticipated form for the dilaton interaction creates a serious roadblock for inflation and makes it unlikely that the universe ever reaches a state with zero cosmological constant and time-independent gravitational constant.Comment: 14 pages, 2 figures available as eps files on reques