Calculation of the ground state electronic structures and electronic spectra of di- and trisulfide radical anions by the scattered wave-SCF-X.alpha. method

Abstract

The reasoning used to justify, or rationalize its occurrence for the (j/6-C8H8)M(CO)3 species is such that it would be predicted to occur in (rj6-C8H8)MLn species in general, and also in (ij5-C7H7)ML" species. These predictions are being tested by F.A.C. and John R. Kolb. (31) See, for example, F. A. Cotton, "Chemical Applications of Group Theory", 2d ed,

Ab initio Hartree–Fock–Slater calculations of polysulfanes H2Sn (n = 1–4) and the ions HS and S

“…A similar tendency is observed in the extended Hiickel calculation [S] but the agreement is only qualitative. A scattered wave XLY calculation of S:- [22] also shows more electronic density on the terminal S atoms, the agreement with our results again being only qualitative. This finding is consistent with results from ESCA measurements [23].…”

An integrated spectroscopic approach for the identification of what distinguishes Afghan lapis lazuli from others

“…As is well known, entrapped polysulfide radical species S n À are responsible for the color of lapis lazuli. In particular, S 3 À accounts for blue color, S 2 À for yellow color, while different balances between S 3 À and S 2 À can produce various hues such as green, blue-green, blue, turquoise [16,17]. It is hence reasonable to assume that a hydrogen atom would be bonded to the S n À chains.…”

Mineralogical characterization of the blue pigment of Michelangelo's fresco "The Last Judgment"

“…According to Hassan et al (1985), lazurite has the idealized formula Na 6 Ca 2 (Al 6 Si 6 O 24 )S 2 , but the S 2-is commonly replaced by SO 4 2-groups (Rastsvetaeva et al 2002). Many papers have addressed the origin of the blue color of lazurite and, in particular, of the synthetic equivalent ultramarine (Cotton et al 1976). At present, the explanation of the ultramarine, and therefore lazurite, blue chromophore is the presence of a disordered S 3 -group (S-S bond distance of ca.…”