Search results for "SPECTRA"

Über gemischte bindungen in der IV. Hauptgruppe

1984

Abstract The reaction of Ph 3 PbLi with Ph 3 SnCl or Ph 3 GeCl gives Ph 3 PbSnPh 3 and Ph 2 PbGePh 3 , respectively; there is no reaction with Ph 3 SiCl. Ph 3 SiLi reacts with Ph 3 PbCl to form a regular 1 : 1 Pb 2 Ph 6 · Si 2 Ph 6 phase. The compounds have been investigated by mass, NMR and vibrational spectra: 207 Pb NMR chemical shifts with respect to PbMe 2 −79.8 (Pb 2 Ph 6 ), −256.5 (Ph 3 PbSnPh 3 ), −271.5 ppm (Ph 3 PbGePh 3 ); stretching vibrations 112 (PbPb), 125 (PbSn), 138 cm −1 (PbGe). The crystal structures have been determined and refined to R = 0.061 (Ph 3 PbSnPh 3 , −40°C), 0.053 (Ph 3 PbGePh 3 , −50°C), 0.068 (Pb 2 Ph 6 · Si 2 Ph 6 , 20°C); bond lengths 285 (PbPb),…

Fluoreszenz‐Untersuchungen an styrylsubstituierten Benzolen

1986

Die Fluoreszenz-Abklingzeiten der stilbenartigen Verbindungen 1 – 4 zeigen, das die mittleren Lebensdauern dieser Molekule im elektronisch angeregten Singulettzustand um rund zwei Zehnerpotenzen hoher sind als bei trans-Stilben selbst. Anhand von UV-Absorptions-und Anregungsspektren wird das auf einen neu gefundenen S1-Zustand zuruckgefuhrt, der einem verbotenen Ubergang S0 S1 auf der langwelligen Seite der intensiven Absorption entspricht. Investigations on the Fluorescence of Styryl-substituted Benzenes Fluorescence decay measurements of the stilbene-like compounds 1 – 4 demonstrate that the average lifetimes of these molecules in the electronically excited singlet state are about 102 tim…

Influence of Au, Ag, and Cu Adatoms on Optical Properties of TiO2 (110) Surface: Predictions from RT-TDDFT Calculations

2022

This study was financially supported by Flag-ERA JTC To2Dox project (S.P.) and M-ERA-NET2 project SunToChem (E.A.K.). M.G.B. thanks the support from the Program for the Foreign Experts (Grant No. W2017011) offered by Chongqing University of Posts and Telecommunications and the National Foreign Experts Program for “Belt and Road Initiative” Innovative Talent Exchange (Grant No. DL2021035001L), Estonian Research Council grant PUT PRG111, European Regional Development Fund (TK141), NCN project 2018/31/B/ST4/00924. Institute of Solid State Physics, University of Latvia, as the Center of Excellence, has received funding from the European Union’s Horizon 2020 Framework Program H2020-WIDESPREAD-01…

Complexes of diorganotin(IV) dihalides with diphosphoryl compounds and their Mössbauer spectra

1993

Kristallstruktur, thermische Ausdehnung und Farbwechsel von (Me3Ge)2Sb-Sb(GeMe3)2 und anderen Distibanen

1989

Abstract Single crystals of the distibanes (Me3M)4Sb2 (1: M = Si, 2: M = Ge) are obtained by the oxidation in air of (Me3M)3Sb. The crystal structure of 2 is reported. 2 forms linear chains of distibane molecules in trans conformation with Sb ··· Sb contacts of 386 pm at −110°C and 390 pm at 22°C. The thermal expansion of crystals of 2 and (Me3Sn)4Sb2 (3) has been determined. UV-VIS spectra of 1–3, Me4Sb2 (4), Et4Sb2 (5), and Ph4Sb2 (6) in different phases have been recorded. The spectra of 1–5 are consistent with the visible colour changes.

Synthese und Strukturen neuer Eisen-Sauerstoff-Alkoxid-Cluster

2004

Der Eisen-Sauerstoff-Alkoxy-Cluster [Fe9O3(OC2H5)21]·C2H5OH kann unter unterschiedlichen Bedingungen zu Molekulen umgesetzt werden, denen alle die allgemeine Formel [Fe5O(OR)8(OR′)5] gemeinsam ist. Erwarmt man [Fe9O3(OC2H5)21]·C2H5OH in Toluol, so entsteht [Fe5O(OC2H5)13], das durch Kristallisation abgetrennt werden kann, wohingegen ein Auflosen von [Fe9O3(OC2H5)21]·C2H5OH in tert-Butylamin zum 1 : 2-Addukt [Fe5O(OC2H5)13]·2 t-Bu-NH2 fuhrt. Mit Triethyl- oder Triphenylsilanol entsteht aus [Fe9O3(OC2H5)21]·C2H5OH wieder ein Sauerstoff-Eisencluster des gleichen Motivs: [Fe5O(OC2H5)8{OSi(C2H5)3}5] bzw. [Fe5O(OC2H5)8{OSi(C6H5)3}5]. Die Molekulstruktur [Fe5O(OC2H5)8{OSi(C2H5)3}5], die uber Rontg…

A heptanuclear Fe(II)–Fe(III)6 system with twelve unpaired electrons

2000

Abstract The pentadentate ligand 5 LH2 = saldptn = N,N′-bis(1-hydroxy-2-benzyliden)-1,7-diamino-4-azaheptane has been prepared by a Schiff base condensation between 1,7-diamino-4-azaheptane and the corresponding salicyaldehyde. Its complexation with Fe(III) gave the high-spin (S=5/2) complex of [Fe III ( 5 L)Cl]. This precursor was combined with [Fe(CN)6]4− and a blue heptanuclear complex [FeII{(CN)Fe III ( 5 L)}6]Cl2 resulted. This system belongs to the class of high-spin molecules possessing twelve unpaired electrons (S=6) as proven by the magnetic susceptibility measurements and Mossbauer spectra.

Crystal structure, magnetic properties and esr studies of (4-apyH)4[CuIIBr4] [CuIBr2]2: a novel Cu(II)⧹Cu(I) system containing bromocuprate(I) chains…

1998

Abstract The synthesis, crystal structure, ESR spectra and magnetic properties are reported for the Cu(II)⧹Cu(I) compound (4-apyH)4[Cu3Br8] (4-apyH = C5H7N2 = 4-aminopyridinium). Single-crystals of the compound were grown by slow diffusion of n-hexane on an ethanolic solution of (4-apyH)2[CuBr4] · H2O. The crystal structure is made up of organic cations, isolated [CuIIBr4]2− anions and infinite [CuIBr2]nn− chains composed of edge-sharing CuIBr4 tetrahedra. N–H · · · Br hydrogen bond interactions between organic counter cations and inorganic anionic units are present and contribute to the cohesiveness of the crystal packing. Magnetic susceptibility measurements showed a good isolation of Cu(…

Copper(II) Complexes with Derivatives of Barbiturate

1984

Abstract NaCuL2(OH).1,5H2O, KCuP2(OH).1H2O, Na2CuL4 and K2CuP4-8H2O (HL=Phenobarbitone and HP=Methyl Phenobarbitone) were prepared and characterized by elemental analysis, IR and electronic spectral data and magnetic susceptibility measurements. The ESR spectra show and octahedral environment for the Cu(II) ion.

GIAO/DFT 13C NMR Chemical Shifts of 1,3,4-Thiadiazoles

2007

1 H, 13 C and 15 N NMR spectra of 2-acetylamino-1,3,4-thiadiazole and its 5-substituted derivatives have been measured and assigned based on reference data, as well as homo- and heteronuclear 2 D NMR experiments. In addition, the GIAO/DFT approach at the B3LYP level of theory using the 6-311G basis set was used to calculate the 13 C NMR chemical shifts. Although this method gives reliable results for 2-arylhydrazones of 1,3-diphenylpropanetrione, 2-phenacylpyridines, (Z)-2-(2-hydroxy-2-phenylvinyl)pyridines, 4-fluoroanilines, (1Z,3Z)-1,4-di(pyridin-2-yl)buta-1,3-dienediols and their tautomeric forms, the calculated chemical shifts for the 1,3,4-thiadiazoles studied are less satisfactory. Pr…