R and Raman Spectra

The PTFE film turns black and the product exhibits a 2100-2200 cm" band, characteristic of the C=C bond in the i.r. and Raman spectra. It might be worth noting that, in the experience of some, pure condensed molecules of these types are known to explode violently. 

A. Preparation and Structure.—-A study of the i.r. and Raman spectra of t-butyltetrafluorophosphorane (34 n = 1) has indicated that it is a trigonal bipyramid with the t-butyl group equatorial. The preparation... 

The i.r. and Raman spectra of the cyclic phosphate (104) and its SbCls complex have been assigned and force constants and bond orders calculated. The high frequency of vp o (1308 cm ) may be due to a strong... 

From the studies made by I.R. and Raman spectra on 1,2-dihaloethanes, the conclusion has been that the gauche form is more important in polar than in non polar solvents. This is because that the gauche form has a considerable dipole moment while the anti has nearly none. Solvation by polar solvents reduces the potential energy of a dipole and so makes the gauche form more stable relative to the anti. 

Stereochemical Aspects.—The i.r. and Raman spectra of ethylphosphine and its deuteriated analogue (99) indicate that the fluid phases contain gauche- and trans-conformers, but the solid phase contains the /ra/w-conformer only. The methyl... 

Chloro-, Bromo-, and lodo-complexes. The effect of pressure on the kinetics of the reaction between solid NaCl and ZrC or HfCl4 vapours has been investigated. The i.r. and Raman spectra of solid ZrCl4,2NOCl and HfCl4,2NOCl have shown that they consist of NO and octahedral hexachlorometallate ions. °° Normal-co-ordinate analyses have been reported for the [ZrX ] " and [HfXg] ions (X = Cl or Br). ° ... 

MBrj and MOBrj (M = Nb or Ta) may be obtained by the reaction of BBrj with anhydrous MCI5 or M2O5, respectively. The far-i.r. and Raman spectra of these pentabromides and NbOBr3 were also reported in this study. 

The copper atom in PPh3CuBF4 is trigonally distorted tetrahedrally co-ordinated with the tetrafluoroborate group weakly bonded via a terminal F—Cu linkage (2.31 A). The i.r. and Raman spectra of the complex were recorded, and the vibrations of the co-ordinated BF4 group assigned.643... 

I.r. and Raman spectra have been recorded for a series of octahedral trimethyl-phosphine complexes including trans-[RhX2(PMe3)4]+, and mer- and /ac-[RhX3 (PMe3)3] (X = Cl or Br), and vibrational assignments proposed.206 N.m.r. spectra were also reported and discussed, together with data from 1H-31P indor measurements.207... 

The anions [Pt2X4(CO)2]2- (X = Cl or Br) have been isolated as their [Pr4N] + salts in two crystallographic forms by reaction of K2PtX4 with CO in concentrated HX solution.1171.r. and Raman spectra are indicative of structure (27) having a Pt—Pt bond with 45° rotation of the PtX2CO planes giving rise to cisoid and transoid... 

I.r. and Raman spectra were interpreted in terms of linear anions. In addition, far-i.r. and Raman spectra of the solid [AuXL] (L = PPh3 or AsPh3 X = Cl or Br) and Raman polarization data in solution have enabled identification of the Au—P and Au—As stretching modes.223... 

The pentadeuteriophenylated antimony derivatives (Cg H5)Sb(SCH,CH2)2X of the general structure 24, where X = O or X = S, have been synthesized in five steps, as shown in equation 36, starting with perdeuterated nitrobenzene. The I.R. and Raman spectra of cyclic dithiolates 24 have been determined in the 3200-100 cmregion. The... 

C[CH2AsO(OH)2]4, 97-H or 97-D. Reduction of 97 with SO2 in MeOH regenerates 94. The I.R. and Raman spectra of 94-H and 94-D as well as bond lengths and bond angles of 94 have been presented. 

Such investigations are appropriately performed on spectra of isotopically dilute samples, especially those deuterated to about 5%, (see Sect. 2.6). Most studies carried out during the last decade used this technique. Infrared and Raman spectra of samples deuterated to about 5% are shown in Fig. 4. The OD and OH bands of HDO molecules present in samples deuterated to about 5 and 95%, respectively, are due to uncoupled, local modes (see Sect. 2.6) thus, the frequencies of the bands observed in the i.r. and Raman spectra must be equal (see Fig. 4). 

The water bands of both i.r. and Raman spectra are most sensitive to even small structural changes. Therefore, vibrational spectroscopy is an even better tool for studying phase transitions of solid hydrates than most other experimental techniques, such as X-ray studies and thermal analyses (DTA, DSC). A great many studies of this topic have been reported (see, for example, Refs. 101, 102,153). 

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