The feasibility of simultaneous analysis of mixtures containing two to four butene isomers and up to six total components using process mass spectrometry is assessed. As for typical (nonisomeric) applications of process mass spectrometry, simultaneous analysis is based on the assumption that the electron ionization mass spectra of mixtures are linear combinations of the spectra of the individual constituents. Limits of detection for binary isomer mixtures are on the order of 0.1% to 10%, limited by the ability to distinguish small differences between similar spectra. As spectral and mixture complexity increase, both accuracy and precision decrease. Not surprisingly the similarity of the spectra of stereoisomers cis- and trans-2-butene is greater than that of the other (nonstereoisomeric) isomer pairs, and mixtures containing both cis- and trans-2-butene are the most difficult to quantitate. However, even for mixtures of all four butenes, accuracy (root-mean-square error = 2.43%), precision (average coefficient of variation = 6.72%), and linearity (correlation coefficient of a plot of measured versus actual concentration r2 = 0.985 +/- 0.002) are reasonably good.
The unusually stable vanadyl(IV) and copper(II) dicyclohexyldithiophosphinate complexes, VO[S2P(CeHii)2]2 and Cu[S2P(CeHii)2]2, have been prepared and characterized using infrared, mass, electronic, and electron spin resonance spectroscopy. The esr spectra of the complexes exhibit considerable phosphorus superhyperfine splitting in the solid state and solution which is essentially isotropic. The electronic spectra are interpreted in terms of crystal field calculations and the properties of the complexes are discussed in terms of extended-Hückel molecular orbital calculations for the model compounds VO(S2PX2)2 and Cu(S2PX2)2 (X = H,F).
A novel variation of the weak ligand field treatment of the electronic spectra of transition metal complexes of the type MA,B, with C,, symmetry is presented and tested with data for various pseudotetrahedral cobalt(I1) compounds. A marked improvement in fit of theory to experiment is found over previous models. The explicit account taken of some covalency effects without incurring additional complexity of the model may alleviate some of the conceptual shortcomings inherent in the electrostatic point-charge approximation to metal-ligand interactions while retaining its attractive simplicity.
AIC40105P
IntroductionThe extensive growth of transition metal chemistry has necessitated the development of models to account for and predict the electronic spectra and magnetic properties of complexes possessing lower than cubic symmetry. Compounds possessing metal ions with d' ,9 electronic configurations have been examined'-3 but complexes with other dn configurations have received less attention. The electronic spectra of high-spin cobalt(1I) 3d7 complexes of the types Cox4, CoA3B, and CoA2B2 (X, A, B = monodentate ligands)
Der Komplex (I) wird nach Literaturzitaten erhalten, und die Komplexe (II) werden durch Reaktion der Metallsalze mit stöchiometrischen Mengen der Liganden in absolutem Äthanol dargestellt.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.