Yields theoretical

Calculation of Yield. The yield of a compound obtained in an organic preparation, in addition to being stated in grams, should also be calculated as a percentage of the yield theoretically possible from the weight of the original... 

The efficiency of a synthetic transformation is normally expressed as a percent yield or percentage of the theo retical yield Theoretical yield IS the amount of prod uct that could be formed if the reaction proceeded to completion and did not lead to any products other than those given in the equation... 

M. Dente, E. Ran2i, and S. Barendregt, "Adiabatic Cracking Yields Theoretically Predicted," paper presented stHIChE Meeting, New Orleans, July 1981. 

Rotational Barrier in Ethylene. It is well known that the rotational barrier of the ethylene molecule cannot be adequately described by a single reference Hartree-Fock calculation SCF calculations on this level resulted in values of 126 kcal/mole (30) and 129 kcal/mole (31) whereas the experimental value is 65 kcal/mole (32). Open-shell ab initio calculations of double zeta+polarization quality give the more acceptable value of 48 kcal/mole (33). Inclusion of correlation such as in CEPA calculations yield theoretical results within the experimental error bar (34), albeit at a considerable computational cost. 

The ability of Sadlej basis sets [37] to provide reliable values of has been tested in a limited number of cases with encouraging results [11]. In the present work on benzene the Sadlej basis set yields theoretical estimates close to those obtained by Perrin et al. [16] and Kama et al. [17], but smaller than those reported by Augspurger and Dykstra [18]. The C-C bond distance retained in [18], however, is 1.397 A, compared to 1.395 Aused by us, see Refs. [38] and [40]. 

Experimental vibrational frequencies for the nvjb = 3nat — 6 = 6 vibrational modes of CH3 are available 3002, 580, 3184, 3184, 1383, and 1383 cm-1. The motion of the atoms in the six normal modes is illustrated in Fig. 8.7. Modes 3 and 4 are degenerate, as are modes 5 and 6. The ab initio calculations yield theoretical vibrational frequencies in reasonably good agreement with experiment 2932.4, 275.0, 3090.0, 3090.0, 1375.0, and 1375.0 cm-1. If neither experimental nor theoretical vibrational frequencies are available, which is often the case, one has to simply estimate them by analogy with similar vibrational... 

Yield.—Theoretical (9 gms.). Yellow needles insoluble in water somewhat soluble in benzene and the usual organic solvents soluble in glacial acetic acid M.P. 277° sublimes at 250° B.P. 382°. (Z. a., 19, 669.)... 

Yield.—Theoretical (16 gms.). White crystals almost insoluble in cold water, ether, and ligroin fairly soluble in hot water easily soluble in alcohol M.P. 127°. (B 16, 2597.)... 

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