Spectroscopic properties mass spectra

The formation and the spectroscopic properties of the [Ru(CO) I ] species can be easily studied in different solvents by reacting RuCCO) directly with the iodide promoters (HI, Nal etc,). Thus the hydrido species HRu(00)313, which up to now was not well characterized has been obtained in concentrated solutions in different solvents at room temperature from Ru(CO) I and gaseous or aqueous HI. ( Mass spectrum M/e 567 (M+) 539 (M -CO) 511 (M+-2C0) 483 (M+-3C0)). 

Tetrakis(acetato)ditungsten(II) is a very air-sensitive, bright yellow, diamagnetic solid. It is moderately soluble in THF and acetonitrile but solutions in the latter solvent decompose after several hours. The 360 MHz XH NMR spectrum (in THF-d8) consists of a single methyl resonance at S 2.91. The mass spectrum (solid probe, electron impact, 40-70-eV ionizing voltage) shows the parent ion multiplet at m/e 604. Other spectroscopic data and physicochemical properties are described in the literature.8... 

In the mid 2000s, we initiated a comprehensive study of the coordination properties of orf/zo-phenylene bridged PBs. The DPB 8a was found to react with half an equivalent of [Rh2(g-Cl)2(nbd)2] in dichloromethane at room temperature (Scheme 62) 23 The yellow complex 108 that formed spontaneously was collected (92% yield) and analyzed spectroscopically. The 1H, 13C, and 31P NMR data substantiated the displacement of the labile nbd ligands at rhodium by the phosphine moieties. In addition, the mass spectrum indicated a dimeric structure of general formula [Rh2( i-C1)2(DPB2] and the nB NMR resonance signal observed at... 

Finally, the ketone was reduced by the modified Wolff-Kishner method (cf 8) to give the final product which was free of detectable amounts of the 2,4-isomer. The 200 MHz XH NMR and mass spectrum are both in accord with the structure (cf 1). Full details of this synthesis and spectroscopic properties of the intermediates and final products will be reported elsewhere. 

First, wc purify the compound and determine its physical properties melting point, boiling point, density, refractive index, and solubility in various solvents. In the laboratory today, we would measure various spectra of the compound (Chap. 13), in particular the infrared spectrum and the nmr spectrum indeed, because of the wealth of information to be gotten in this way, spectroscopic examination might well be the first order of business after purification. From the mass spectrum we would get a very accurate molecular weight. 

There are very few experimentally-recorded spectroscopic data for COBrF, and only one publication [1596] exists in which the spectroscopic properties of COBrF have been studied for their own sake. Apart from the recording of a F n.m.r. spectrum and a mass spectrum [1163], the remaining spectroscopic studies of COBrF have been confined to the recording of its infrared spectrum [1596], and to the derivation of spectroscopic correlations with other members of the carbonyl halide series [604,864,1860],... 

Ochromianine, a constituent of the bark of Ochrosia miana, exhibits a mass spectrum virtually identical with that of the isomeric 10-methoxydihydrocorynan-theol. ° The spectroscopic properties of ochromianine suggest that it is a 6-methoxyindole derivative, and that it contains a 3a, 15a-hydrogen configuration, but the configuration at C-20 cannot be regarded as established. The related oxindole A, ochromianoxine (75), accompanies ochromianine in the plant. 

It should be remembered that the mass spectrum does not tell us the positions of the groups on the aromatic rings. This can be answered readily by other spectroscopic techniques or by comparison of physical properties with an authentic sample. 

The physical properties of CPD and DCPD are given in Table 1. DCPD, 3a,4,7,7a-tetrahydro-4,7-methano-li7-indene, can exist in two stereoisomers, the endo and exo forms. Because commercially available DCPD is mostly the endo isomer, the properties in Table 1 are pertinent to those of the endo isomer. Spectroscopical information on CPD and DCPD can be found in (20) (mass spectrum), and (21) (nmr spectrum). References 2 (ir, nv, and Raman spectra). 

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