Rhomboid dimer

LiH molecules can form a much more stable rhomboidal dimer. Hence, we should transform the simple prototypical equation above to the one shown below in reaction (3). The bonding mechanisms operative in reactants and products are shown in Fig. 16. 

Because the crystal structure of the CuBr Et2S adduct 2 has not yet been described, we have grown single crystals in form of large colorless blocks from heptane and determined the solid-state structure. It is surprising, that the architecture of the resulting 1D network differs much from that of [(Et2S)3 Cu4(p.3-I)4 ] 1 and consists of centrosymmetric rhomboid Cu dimers [Cu(l) S distances 2.297 (10) and 2.298(9) A, Cu(l)—Cu(l) distance 3.0454(7) A], which are linked to a... 

Djordjevic, C., M. Lee-Renslo, and E. Sinn. 1995. Peroxo malato vanadatcs(V) Synthesis, spectra and structure of the (NH4)2[V0(02)(C4H405)]22H20 dimer with a rhomboidal V202(hydroxyl) bridging core. Inorg. Chim. Acta 233 97-102. 

Infrared absorption spectra have been measured for NaF and KF isolated in solid argon. The fundamental modes of these species and the B3u, B2u, and Blu modes of (NaF)2 and (KF)2 are assigned assuming a planar rhomboid structure of D2h symmetry for the dimers.171 Surface ionization of lithium and its halides has been studied by a double-filament technique. At relatively high temperatures the temperature dependence of the lithium surface ionization current from all molecules studied was identical with that from lithium. Incomplete dissociation of LiCl can account for Li ionization threshold temperatures well above that for surface ionization of Li atoms. Dissociation energies of 4.8 0.1 eV for LiCl(g) and 4.3 0.1 eV for LiBr(g) were obtained.172 The equilibrium ionic forms in salt vapours have been studied. The concentration of M+ and X ions in the saturated vapours of MX (M = Na or K, X = halogen) at 850 °C is 107—1010 ions cm-3 and the concentration of M2X+ and M2X ions is 109—1011 ions cm-3, so that the vapours exhibit measurable electric conductivity. The equilibrium constants for the gaseous reactions are as follows ... 

I. Rhomboidal, Parallelogram, Distorted Cubane, and Dimer-of-Dimer Shapes... 

The prototypical ethene -i- ethene cycloaddition has been explored computationally and a somewhat different picture has emerged. The Cl for ethene dimerization is calculated to be rhomboid. ... 

FIGURE 16 In the crystal structure of Ru4Gdi6)Br23, two edge-connected IZ2R10I dimers are cormected via common edges to a tetrameric cluster Z4Ri6l = Z4R ioR 6) (left), in which the four Z atoms form a rhomboid. 

Fig. 29 QR PP CCSD(T) (filled rhomboids), 4c-BDF (PBESIC) (filled squares), 4c-DFT (B88/ P86) (filled triangles) and experimental (open squares) dissociation energies, D, and bond lengths, / e. of group-12 dimers (see Table 14). Reprinted with permission from V. Pershina,...

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