W dimers

As will be discussed in detail in the next section, when the reduction of the parent compound 6 was conducted at low temperature (—20 °C) with 2 equiv. of Na in tetrahydrofuran (THF) saturated with ethylene, complete salt removal was achieved, and the r 2-ethylene complex 20 was isolated.22 Upon irradiation, the latter released ethylene, behaving as a source of the d2 [W / -Bu -calix[4]-(0)4 ] carbenoid, which coupled to give a new W=W dimer [W=W, 2.582(1) A], isolated as the bis-Bu NC adduct 21. In H NMR, 21 exhibits a C5-symmetric pattern of signals for the calix[4]arene moiety. 

Development of triple bonded Mo and W dimers, and the idea of an inorganic functional group. ... 

Dimeric M2(CH2SiMc3)6 (M = Mo, W) compounds are prepared by reduction of M0CI5 or WCle in ether with Me3SiCH2MgCF. Both the Mo and W dimers exhibit... 

Reaction with unsaturated organic compounds can produce complex coupling and insertion products e.g., irradiation of the W dimer and dimethylacetylenedicarboxylate gives" (h5-C5H5)3W3(C0)J/j,-h2 h2-C(0)C2(C0jMe)j] in 55% yield and (h -C5H5)2Wj-(CO/jLi-MeOjCCjCOjMe) in 20% yield. 

Alajarm, M., Pastor, A., Orenes, R.-A. and Steed, J. W., Dimeric self-assembling capsules derived from the highly flexible tribenzylamine skeleton, /. Org. Chem., 2002, 67, 7091-7095. 

N2O4 Dinitrogen tetroxide W Dimer of NO2 2NO2 (g) N2O4 (g) + heat... 

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