Methanol, bond angles structure

Diffuse functions have very little effect on the optimized structure of methanol but do significantly affect the bond angles in negatively charged methoxide anion. We can conclude that they are required to produce an accurate structure for the anion by comparing the two calculated geometries to that predicted by Hartree-Fock theory at a very large basis set (which should eliminate basis set effects). 

Methanol, CH3OH. (a) Lewis structure and (b) ball-and-stick model.The measured H — 0 — C bond angle in methanol is 108.6°, very close to the tetrahedral angle of 109.5°. 

The bond lengths and bond angles for the molecules, methanol, acetic acid, and formic acid are given in Table III. The methanol geometry was taken from microwave spectroscopy [17], while the formic and acetic acid geometries were taken to be those of the dimers, found by gas phase electron diffraction [14-15, 13]. X-ray structural parameters were used for crystal packing studies of formic acid [32] and neutron diffraction data for acetic acid [33]. The hydrogen atoms for the molecules in their crystalline forms were positioned as described previously [46, 47]. 

Enders et al. isolated the first triazol-5-ylidene 79 by thermal a-elimination of methanol from 5-methoxytriazoline in 1995 (see Scheme l.lOa)." 79 was stable up to a temperature of 150 °C. "C NMR spectroscopic [<5(C5)=214.6 ppm] and structural parameters such as the short Cca bene N bond lengths [1.351(3) A and 1.373(4) A] and the small N-Cearbene N bond angle [100.6(2)°] confirmed similar properties of 79 and the unsaturated imidazol-2-ylidenes 89. NHC 79 showed no tendency to dimerize to the entetraamine and thus also behaved ehemically like an unsaturated imidazol-2-ylidene. 

The above dimer of 2-(o-bromophenyl)-4,5-diphenyl-imidazolyl radical recrystallized from methanol is linked in the 1,2 positions and the compound is, therefore, 2,2 -bis(o-bromophenyl) - 4,4, 5,5 - tetraphenyl - 1,2 - biimidazole. The molecular configuration was determined by X-ray crystal structure analysis. The measured atomic coordinates are given in Table m, the bond lengths in angstrom units and bond angles are listed in Table TV and dihedral angles between various planes of the dimer molecule are stated in Table V. 

The number of bisylides, in which the carbon atom is stabilized by two neutral sulfur compounds, is restricted so far to one example, C(S NMe Ph2)2, with sulfur (IV). The proton of the conjugated acid (HC(S NMe Ph2)2) can be reversibly removed on an ion exchange resin loaded with OH protonation is achieved with 10% HCIO4 in methanol as shown in Fig. 8. The bent structure with an S-C-S angle of 117° and bond shortening of the C-S bond upon deprotonation of the related cation proves this compound as a typical carbon(O) compound stabilized by the Lewis base S(NMe)Ph2. Although the compound was reported to be stable even... 

A comparison of the water spectrum of water-methanol mixtures with the spectrum of liquid water shows that the angle distribution of H-bonds is sharper at (3 = 0 and j3 = 180°. The cyclic structures of water with medium (3-values of Fig. 5 seem to... 

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