Electronic spectra interpretation

N-Do/Jor Ligands. The full account of the preparation and properties of V[N(SiMc3)2]3 has been published. (Et4N)3[V(NCSe)e] has been prepared and its electronic spectrum reported in several solvents. The electronic spectra of fVL lfNCSij complexes (L = py, 3-picoline, 3,4-lutidine, or 3,5-lutidine) are consistent with tetrahedral microsymmetry about the V " atom, and the magnetic properties of V complexes with the thiosemicarbazones of salicylaldehyde and pyruvic acid have been interpreted in terms of a tetragonal environment about the metal. ... 

Binary Systems and Related Compounds.—Halides. The thermodynamics of gas-phase equilibria in the W-F2 and W-F2-H2 systems at high temperatures have been described.The Raman spectrum of solid MoF exhibits Mo—F stretching bands at 746, 722, and 690 cm These results suggest that the compound has a similar structure to NbF4, with each molybdenum co-ordinated to six fluorine atoms.The Raman spectrum of crystalline M0F5 has also been reported and interpreted in terms of the crystal structure.The electronic spectrum of liquid M0F5 has been determined and shown to be consistent with a trigonal-bipyramidal molecular unit. ... 

The following bands of the PE spectrum of dimethyldiazirine were reported IP(v) 12.1, ZP(n+) 13.3, ZP(n ) 9.75 eV. Thus the i/r(7r)-orbital lies between the orbitals of the lone electron pairs. Interpretation of the spectrum suggested that the lone electron pairs are not so lonely, but are localized at the N atoms to only 56% and 43% respectively (73HCA1933). This effect is known, but less markedly, from (Z)-azomethane. PE spectra of the parent diazirine and the difluoro compound were also recorded. Comparison with calculated spectra gave good agreement (72JCP(57)1758). 

This chapter consists of the application of the symmetry concepts of Chapter 2 to the construction of molecular orbitals for a range of diatomic molecules. The principles of molecular orbital theory are developed in the discussion of the bonding of the simplest molecular species, the one-electron dihydrogen molecule-ion, H2+, and the simplest molecule, the two-electron dihydrogen molecule. Valence bond theory is introduced and compared with molecular orbital theory. The photo-electron spectrum of the dihydrogen molecule is described and interpreted. 

Aside from attempts to interpret the electronic spectrum of thiophene in terms of the MO method,18,31,33,84,36,41 successful use of the... 

The products isolated from reactions of amides with transition metal halides usually contain coordinated halide (e.g. the formulations in Table 2). In some cases such as [Co(NMF)6][CoCLt], halide and amide are coordinated to different metal atoms, but when such compounds are dissolved in the neat ligand, halide can be replaced and at high dilution all the metal ions may be fully coordinated by the amide alone. The electronic spectrum resulting when this cobalt complex is dissolved in nitromethane has been interpreted as relating solely to the tetrahedral complex [CoC12(NMF)2]. 

In the solid state, the phenyl nuclei of biphenyl are coplanar (Dhar, 1932 Kitaigorodsky, 1946 Rizvi and Trotter, 1961). Bastiansen (1949) reports that the angle between the rings is 45° in the gas phase as determined by electron diffraction. The conformation of biphenyl in solution is not established (Wheland, 1955). It has been argued to be coplanar on the basis of the Kerr constant (Chau et al., 1959). Recent observations of the electronic spectrum of biphenyl and certain derivatives in the solid, liquid, and vapor states were interpreted as indicative of a 20° deviation from coplanarity in solution (Suzuki, 1959). 

The first investigation into the excited states of ZnPc based on first-principles methods is the TDDFT/SAOP study by Ricciardi et al [135], where the UV-vis and the vacuum ultraviolet region of the electronic spectrum of ZnPc are described in detail. Subsequently, Nguyen and Pachter, in the context of a TDDFT/B3LYP study of the electronic spectroscopy of the zinc tetrapyrrole series [140], ZnP, ZnPz, ZnTBP, and ZnPc, came to a somewhat different interpretation of the Uv-vis spectrum of this phthalocyanine. 

The electronic spectrum of 1,5-diphenylpentadienyllithium in thf shows the presence of contact (tight) and.solvent-separated (loose) ion pairs. The smaller the cation and the more delocalized the anion, the greater is the tendency to form loose ion pairs. They are also favored as the temperature is lowered (64,65). 13C-NMR studies (66,67) have been interpreted in terms of appreciable covalency, but the present view is that organolithiums are predominantly ionic (68). Schlosser and Stahle have analyzed coupling constants 2J(C—H) and 3J(H—H) in the 13C- and H-NMR spectra of allyl derivatives of Mg, Li, Na, and K and of pentadienyls of Li and K (69). They conclude that considerable pleating of the allyl and pentadienylmetal structures occurs. The ligand is by no means planar, and the metal binds to the electron-rich odd-numbered sites. The lithium is considered to be q3 whereas the potassium is able to reach t]5 coordination with a U-shaped ligand. 

S-Donor ligands. As an extension of previous studies on related complexes of iron(n), cobalt(n), nickel(n), and zinc(n), the structure of Mn[SPPh2-N PPh2S]2 has been determined by X-ray methods. The metal atom is co-ordinated in an approximately tetrahedral manner by the four sulphur atoms. The two MnS2P2N rings adopt the twisted boat conformation with S and P atoms at the apices. The single-crystal electronic spectrum has been measured and interpreted.92... 

S. Zilberg, Y. Haas, S. Shaik, J. Phys. Chem. 99, 16558 (1995). Electronic Spectrum of Anthracene An ab-initio Molecular Orbital Calculations Combined with a Valence Bond Interpretation. 

While the study of solvatochromic dyes is well established as a means of probing solvent polarity, these are not the only solutes that can be used in this fashion. A more exotic solvatochromic probe is an excess electron in solution. Optical absorption studies of the thermalized (solvated) electron generated in the pulse radiolysis of a series of ILs show a strong dependence on cation character, with a relatively low frequency for tetraalkylammonium systems and a higher frequency for cyclic (pyrrolidinium-based) cations [48, 207]. The solvated electron spectrum is often interpreted in a particle-in-a-box framework, which would imply that the cyclic cations (which possess smaller ionic volumes) simply coordinate more closely with the electron and so create a smaller domain in which the electron must localize. The breadth of the absorptions and their maximum fall within the range of values expected for moderately polar organic solvents. 

Electronic spectra of Bk(III) (99) and Bk(IV) (100) and a prediction of the electronic spectrum of Bk(II) (101) have been published. Spin-orbit coupling diagrams for these berkelium ions, based on a free-ion interpretation of the f-f spectra, were proposed. 

Interpretation of the Electronic Spectrum of Free Base Porphin... 

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