Crystal organic

The general remarks regarding energy which we have made in Chaps. IX and XXII apply here also. The interatomic forces within the molecules can be well represented by Morse curves, as in Chap. IX, Sec. 1. In Table XXV-2 we give values of D and re for the most important bonds 

Bond energies taken from Pauling, J. Am. Chem. Soc., 54, 3570 (1932). 

Latent heats are in kilogram-calories per mole, taken from Landolt s Tables, and are for the lowest available temperature in each case. 

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Filippini G and Gavezzotti A 1993 Empirical intermolecular potentials for organic crystals the 6-exp approximation revisited Acta Crystallogr. B 49 868... 

Overney R, Howald L, Frommer J, Meyer E, Brodbeck D and Guntherodt H 1992 Molecular surface structure of organic crystals observed by atomic force microscopy Ultramicroscopy 42-A4 983... 

To verify effectiveness of NDCPA we carried out the calculations of absorption spectra for a system of excitons locally and linearly coupled to Einstein phonons at zero temperature in cubic crystal with one molecule per unit cell (probably the simplest model of exciton-phonon system of organic crystals). Absorption spectrum is defined as an imaginary part of one-exciton Green s function taken at zero value of exciton momentum vector... 

Gavezzotti A and G Filippini 1996. Computer Prediction of Organic Crystal Structures Using Partial X-ray Diffraction Data, journal of the American Chemical Society 118 7153-7157. 

NEWCRYST FIZ Kadsmhe STN inorganic and organic crystal stmctures... 

Melt Crystallization. Crystallization (qv) from a melt is inherently more attractive than distillation because the heat of fusion is much lower than that of evaporation. It also benefits from lower operating temperature. In addition, organic crystals are virtually insoluble in each other so that a pure product is possible in a one-stage operation. 

M. Pope, C.L. Swenbeig, Electronic Processes in Organic Crystals, Clarendon Press, Oxford 1982. 

M. Pope, C. E. Swenberg. Electronic Pnteesses in Organic Crystals, Oxford University Press, New York 1982. 

The problem of crystallizing glycerol proved to be of some interest. A tube of glycerol ua.r kept with one end in liquid air. the other at room temperature for a period of several weeks without results. Seeding with various organic crystals of similar structure tt s also tried. In fact, the artifices ordinarily used for starting crystallization in the absence of seed crystals were all tried without success. 

The packing energy of an organic crystal can be easily calculated by a lattice sum over pairwise interactions. The potential parameters for these calculations are summarized in Table 15. The packing energy is usually a quite accurate estimate of the crystal sublimation energy. 

Charle, K. P. Spin-Dependent Kinetics in Dye-Sensitized Charge-Carrier Injection into Organic Crystal Electrodes 19... 

These results are significant in understanding the photochemical behaviour of organic crystals at low temperature and in the development of a new synthetic route to highly strained [2.2]paracyclophane derivatives. 

Liquid crystal sounds like a contradiction. Liquids are fluid, their molecules continually changing places in a manner that is not particularly well organized. Crystals are immobile, their molecules locked into fixed positions that form regular patterns. Yet, not only does this unusual combination of fluidity and regular patterns exist, it plays important roles in biological organisms. 

Charge-Carrier Injection into Organic Crystal Electrodes... 

Detection of Higher Order Multiphoton Fluorescence from Organic Crystals... 

Morphology Changes of Organic Crystals by Single-Crystal-to-Single-Crystal Photocyclization 527... 

As already anticipated, the molecular surface we calculate is useful in describing condensed state properties. There is a steady linear relationship between Sn, and packing energy for organic crystals and the suiphoxide and suiphone compounds make no... 

Price SSL, Price LS (2005) Modelling Intermolecular Forces for Organic Crystal Structure Prediction 115 81-123... 

A. Gavezzoti, Calculation of lattice energies of organic crystals. Z. Kristallogr. 220 (2005) 499. 

R. S. Rowland, R. Taylor, Intermolecular nonbonded contact distances in organic crystal structures. J. Chem. Phys. 100 (1996) 7384. 

These values were used to correct the intensities for nine representative data sets, organic crystals, organometallics and minerals, and the data compared with respect to systematic absences and space group assignment (i) with no corrections to the data, (ii) with an absorption correction (SADABS [9]), (iii) with only 1/2 correction, and (iv) with both absorption and X/2 correction. Analogously four different refinements per sample were carried out based on F2. 

Brodersen S, Wilke S, Leusen FJJ, Engel GE (2005) Comparison of static and fluctuating charge models for force-field methods applied to organic crystals. Cryst Growth Des 5(3) 925—933... 

Gusev, A. I. et al. Third All-Union Conf. on Organic Crystal Chemistry and on the Section of Crystal Chemistry of the Structure and Properties of Polymetallic Organometallic Compounds, p. 9, Gorky 1981... 

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