Effect of ionic strength on stability constants. A study of the electronic absorption spectra of the mercuric halides HgX+, HgX2, HgX–3 and HgX2–4 in water

1984 ◽  
Vol 80 (9) ◽  
pp. 2361 ◽  
Author(s):  
Trevor R. Griffiths ◽  
Richard A. Anderson
Keyword(s):  
Ionic Strength ◽  
Absorption Spectra ◽  
Stability Constants ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Mercuric Halides

Tetrahalogenomercury(II) complexes. A study of their electronic spectra, formation constants, ionic strength, and cation effects

1991 ◽  
Vol 69 (3) ◽  
pp. 451-457 ◽  
Author(s):  
Trevor R. Griffiths ◽  
Richard A. Anderson
Keyword(s):  
Ionic Strength ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Formation Constants ◽  
Cation Effects ◽  
Halide Complexes ◽  
First Time

The unambiguous electronic absorption spectra of HgX42−(X = Cl, Br, or I) in methanol have been determined for the first time. The spectra were resolved into their component Gaussian bands, and assigned using a correlation diagram for Td symmetry. The effects of second-order spin–orbit coupling account satisfactorily for the observed band intensities and splittings. The formation constants, K4, as a function of ionic strength were computed over the complete spectral range by multiple linear regression analysis and were, extrapolated to infinite dilution, 0.4 ± 0.1 for Hgl42− and HgBr42−, and 5.7 ± 0.2 for HgCl42−. Significant cation effects were observed upon the spectra of HgX2 with added X−, and may partially be explained in terms of the extended Debye–Hückel equation. Key words: electronic absorption spectra, mercury(II) halide complexes, formation constants, ionic strength, Gaussian band analysis.

Copper(II)-oxime complexes: A structural and spectroscopic study for a diamine dioxime ligand

1972 ◽  
Vol 25 (4) ◽  
pp. 747 ◽  
Author(s):  
JW Fraser ◽  
GR Hedwig ◽  
HKJ Powell ◽  
WT Robinson
Keyword(s):  
Spectroscopic Study ◽  
Absorption Spectra ◽  
Stability Constants ◽  
Electronic Absorption ◽  
Copper Atom ◽  
Electronic Absorption Spectra ◽  
Coordination Environment ◽  
Magnetic Susceptibilities ◽  
X Ray ◽  
Trigonal Bipyramidal

The preparations are reported for copper(11) complexes with the ligand 4,4,9,9-tetramethyl-5,s-diazadodecane-2,l-dione dioxime, LH2. Syntheses from the syn (methyl) and anti isomers of the ligand give the same products. The complexes characterized are Cu(LH2)X2,yH2O (X = Cl-, ClO4-; y = 0, 1, 2) and Cu(LH)X (X = Cl-, Br-, ClO4-). The complex Cu(LH)Br is shown by X-ray structure analysis to contain dimeric units (Cu(LH))22+ with crystallographic C2 symmetry and with the copper atom in a trigonal bipyramidal coordination environment. Stability constants for the reactions Cu2+ + LH2 ←→ Cu(LH2)2+ (log K = 13.24 � 0.05) and Cu(LH2)2+ ←→ Cu(LH)+ + H+ (log K = -3.24 � 0.08) are reported, as well as the magnetic susceptibilities, i.r. spectra, and electronic absorption spectra of the complexes.

Stereochemistry of [carbonato-bis((S)-prolinato)]cobaltate(III) anion

1984 ◽  
Vol 49 (3) ◽  
pp. 680-683 ◽  
Author(s):  
Bohumil Hájek ◽  
Dagmar Sýkorová ◽  
Jiří Chyba
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Cd Spectra

The λ-C1-cis(N), δ-C1-cis(N), λ-C2-cis(N) and δ-C2-cis(N) isomers of the complex K[Co((S)-Pro)2CO3] were chromatographically separated and characterized by their electronic absorption spectra and CD spectra.

Photocolouration of 2,4,4,6-Tetraaryl-4H-pyrans and Their Heteroanalogues: Importance of Hypervalent Photoisomers

1995 ◽  
Vol 60 (10) ◽  
pp. 1621-1633 ◽  
Author(s):  
Stanislav Böhm ◽  
Mojmír Adamec ◽  
Stanislav Nešpůrek ◽  
Josef Kuthan
Keyword(s):  
Reaction Kinetics ◽  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Theoretical Data ◽  
Order Reaction ◽  
Bleaching Process ◽  
First Order ◽  
Photodegradation Products ◽  
Hypervalent Molecules

Molecular geometries of 2,4,4,6-tetraphenyl-4H-pyran (Ia), 4,4-(biphenyl-2,2e-diyl)-2,6-diphenyl-4H-pyran (Ib) and their heterocyclic isomers II-V were optimized by the PM3 method and used for the calculation of electronic absorption spectra by the CNDO/S-CI procedure. Comparison of the theoretical data with experimental UV-VIS absorption spectra made possible to select hypervalent molecules IIIa, IIIb, IVa and IVb being responsible for the photocolouration of 4H-pyrans Ia, Ib, while compounds Va, Vb, VI and VII come into account as possible photodegradation products. The bleaching process of the UV illuminated compound Ia is analyzed in terms of dispersive first-order reaction kinetics.

Niobocene Dichloride and Niobocene Diiodide: Electronic Absorption Spectra and Electron Spin Resonance

1998 ◽  
Vol 63 (5) ◽  
pp. 628-635 ◽  
Author(s):  
Jana Holubová ◽  
Zdeněk Černošek ◽  
Ivan Pavlík
Keyword(s):  
Absorption Spectra ◽  
Electronic Absorption ◽  
Electronic Absorption Spectra ◽  
Point Group ◽  
Esr Spectra ◽  
Ligand Field ◽  
Orbital Interaction ◽  
Symmetry Point Group ◽  
Spin Orbital ◽  
Halide Ligands

The effect of the halide ligand on the bonding of niobium in niobocene dichloride and niobocene diiodide was investigated. The electronic absorption spectra of the two compounds in the range of d-d transitions were resolved into four bands corresponding to transitions of the d1 electron between five frontier orbitals in a molecule of symmetry point group C2v. The energies of the frontier molecular orbitals were determined relatively to the energy of the orbitals in the spherically symmetric ligand field formed by the appropriate halide ligands. The effect of the halide ligands on the spin-orbital interaction of the HOMO orbital is discussed qualitatively on the basis the ESR spectra.

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