Reactions of 1,2-ethanedithiol and 2-mercaptoethanol with unsaturated derivatives of four-coordinate phosphorus acids

The reaction of 1,2-ethanedithiol with diethyl vinylphosphonate in the presence of EtONa occurs as the addition of the sulfhydryl group to the β-carbon atom of the substrate to give 1 : 1 and 1 : 2 adducts. The nucleophilic addition of 2-mercaptoethanol at the β position of the multiple bond of diethyl vinyl-, diethyl allenyl-, and diethyl prop-1-ynylphosphonates involves only the sulfhydryl group.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2156–2159, October, 2004.     

Overtone spectra of 1,2-dichloro- and dibromo-ethanes in the near infrared region

The vibrational overtone spectra of the liquid phase 1,2-dichloroethane and 1,2-dibromoethane in the spectral regions of the CH stretching local mode overtones corresponding to Δυ_CH = 2 to Δυ_CH = 5 are reported. The observed spectral features are assigned using the local mode model. Local mode frequencies ω_CH and diagonal local model anharmonicities X_CH are obtained from an analysis of the spectra. The local-local combinations observed are interpreted on the basis of a coupled CH oscillator model hamiltonian. Local-normal combinations show complex structures and their possible assignments are given.     

Overtone spectra of aniline derivatives

Overtone spectra of 2-ethylaniline, N-methylaniline, N-ethylaniline, N,N-dimethylaniline and N,N-diethylaniline have been studied in 2500-15000 cm(-1) region. Vibrational frequency and anharmonicity constants for aryl/alkyl C-H stretch and N-H stretch vibrations have been determined. The effect of substitution of C(2)H(5) group on the ortho position in the ring and CH(3)/C(2)H(5) at the positions of the H-atom in NH(2) group has been studied in these molecules. It is noted that the aryl C-H stretching frequency and the N-H stretching frequency is appreciably increased due to the replacement of H in NH(2) group by CH(3)/C(2)H(5). These experimental observations are well supported by theoretical calculations for charge density on N-atom using molecular orbital AM(1) method.     

Overtone spectra and anharmonic resonances in haloacetylenes

In this work preliminary results are reported on an extensive vibrational analysis of the molecules HCCX and DCCX with X = F and Cl, in which a number of anharmonic resonances are analysed. The importance of quartic anharmonic resonances in these molecular types is reported involving the effective constants K₁₂₄₄ and K₁₂₅₅, and these are related to the corresponding resonances in acetylene and its isotopomers. The correct analysis of Fermi resonances and quartic anharmonic resonances is important not only in reproducing the high overtone energy levels, but also in fitting the observed rotational constants, and in determining the _r constants and hence the equilibrium rotational constants. In this paper we revise our recent analysis of the equilibrium structure of HCCF in the light of these effects.     

Multicomponent cyclothiomethylation of phenylenediamines and 4,4'-diaminodiphenyls with formaldehyde and 1,2-ethanedithiol

One-pot synthesis of bis-1,5,3-dithiazepanes by cyclothiomethylation of o-phenylenediamine, 4,4'-diaminodiphenyl, 4,4'-diaminodiphenyl oxide, and 4,4'-diaminodiphenylmethane with formaldehyde and 1,2- ethanedithiol was performed. Sorption properties of the newly synthesized bis[4-(1,5,3-dithiazepan-3-yl)-phenyl] oxide were investigated by the batch technique. High efficiency of the recovery of palladium(II) with this reagent from hydrochloric acid solutions at room temperature was shown.     

Oligomerization and cyclization of 1,2-ethanedithiol (EDT), HSCH2CH2SH,by selenium dioxide and iodine

The reaction of 1,2 ethanedithiol (EDT) with selenous acid in water or alcohol leads to selenopolysulfide chains or cycles, (C₂H₄SSeSC₂H₄SS)_n, with randomly distributed  SSeS and  SS moieties. The reaction in water produces incompletely reacted material, which on recrystallization, gives an oligomer corresponding to 5 EDT units (pentamer) as confirmed by molecular mass determination, Se analysis, ¹H- and ⁷⁷Se-NMR spectroscopy. In both the pentamer and cyclic forms the incidence of neighboring  SSeS moieties is higher than that expected statistically. The mechanism for the reaction of thiols with selenous acid provides some rationalization for this observation in as much as neighboring  SSeS groups, or groups that will lead rapidly to neighboring  SSeS groups are formed in general before  SS links can be formed. The Raman spectrum of these products show typical strong SS, SeS, and CS stretching bands at 510, 370, and 730 cm⁻¹. The high frequency of ν_CS is attributed to a preferred gauche conformation at the CS bonds. For comparison, polydisulfides were also prepared from EDT and iodine in methanol. These products consist of at least seven cyclic polymers ranging from the four-membered 1,2-dithietane to higher members. Heating above 100°C in chloroform for several hours gives a solution containing the four lowest molecular mass rings, which on standing for 24 h, precipitate highly insoluble material, which is probably chain or large-ring polymer. Molecular mass determination in camphor indicates that, like yellow sulphur, chain polymers are formed at the melting point of camphor (170°C). © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36 : 379–390, 1998     

Structural diversity of interaction products of mucochloric acid and its derivatives with 1,2-ethanedithiol

The synthesis and characterization of previously unknown sulfur-containing products from the reaction of mucochloric acid (3,4-dichloro-5-hydroxy-2(5H)-furanone) and its 5-alkoxy derivatives with 1,2-ethanedithiol is reported. Under basic and acidic conditions both SH-groups of the reagent show nucleophilic activity, leading to the formation of substitution products of different structural types. Novel fused (7-hydroxy-2,3-dihydro[1,4]dithiino[2,3-c]furan-5(7H)-one) and spiro (9-chloro-6-methoxy-7-oxa-1,4-dithiaspiro[4.4]nonan-8-one) bicyclic compounds, as well as various bis-thioethers have been obtained and characterized by NMR spectroscopy and single crystal X-ray diffraction.     

A new, stereoselective, ring-forming reaction of 1,2-ethanedithiol with N-acylated indoles

While attempting to prepare 2,5-dithiacyclopentyl derivatives from N-acyl 5-fluoroindole by reaction with 1,2-ethanedithiol we discovered that, instead of the expected product, annelation occurred to give a tricyclic compound containing a 3,6-dithiaazepine ring. This reaction is stereoselective and was found to be general for N-acylindoles, not being affected by substituents on the indole ring.     

Solvent properties of ethanediol and 2-mercaptoethanol

The nature of interactions between solutes and the solvents ethanediol and 2-mercaptoethanol were studied employing polarography, cyclic voltammetry and visible spectroscopy. The polarographic and voltammetric behavior of TlClO₄, Zn(CF₃SO₃)₂, Cd(CFP₃SO₃)₂, Pb(CF₃SO₃)₂, Cu(CF₃SO₃)₂, Mn(CF₃SO₃)₂, Co(CF₃SO₃)₂, Ni(ClO₄)₂·2H₂O, oxygen and bis(biphenyl)-chromium(I) tetraphenylborate or iodide were measured. Gibbs energies of transfer based on the bis(biphenyl)chromium assumption were calculated for the transfer from acetonitrile into ethanediol for Tl⁺, Ag⁺, Cd²⁺, and Pb²⁺ as well as for Tl⁺, Cu⁺, Cd²⁺, and Pb²⁺ into 2-mercaptoethanol. The solvatochromic shift of acetylacetonato (N, N, N, N-tetramethyl-ethylenediamine)copper(II) perchlorate was used to evaluate the hard donor properties of ethanediol. The acceptor properties of both solvents were estimated from the low energy visible absorption band of bis(cyano)bis(1,10-phenanthroline)iron(II). The different behavior of ethanediol and 2-mercaptoethanol is discussed on the basis of the changes of half-wave potentials, of Gibbs energies of transfer and of the shifts of the solvatochromic compounds.     

Preparation and proton spectra of 1-aryl-1,2-dihydro-2-quinolones

1-Phenyl-, 1-m-tolyl- and 1-p-tolyl-1,2-dihydro-2-quinolone have been prepared by treating the potassium derivative of 1,2-dihydro-2-quinolone with the corresponding aryl bromide in the presence of finely divided copper. The use of o-bromotoluene in this reaction gave trace amounts of a crystalline material which upon the basis of mass spectrum analysis was assigned 2-o-tolyloxyquinoline as a structure. The 1-aryl groups caused an unusual chemical shift of the 8-proton to the Δ 6.64–6.70 region. This behavior paralleled that observed for the 7-proton of 6-phenyl-6H-indeno[1,2-c]isoquinoline-5,11-dione in earlier studies.     

Cathodic stripping voltammetry of 2-mercaptoethanol

The behaviour of 2-mercaptoethanol at a hanging mercury drop electrode by cathodic stripping voltammetry (c.s.v.) is studied. The stripping curves are recorded by three scanning modes: rapid-scan direct-current, differential-pulse and fundamental harmonic alternating-current polarography. Under the recommended conditions, pre-electrolysis is done at a potential of 0.0 V vs. Ag/AgCl for 3 min in a medium of pH 6.7 or 8 (Britton-Robinson buffer). Then after 1 min, stripping is done at a scan rate of 6.6 mV s^?1 preferably in the differential-pulse mode. The stripping peak at about ?0.4 V is used to determine 2-mercaptoethanol within the concentration range 3 × 10^?8/2-8 × 10^?7 mol l^?1. Calibration functions are reported; the standard additions method is preferred near the limit of detection. The interferences of several organic compounds are described.     

The nickel-catalysed carbonylation of 2-mercaptoethanol

2-Mercapthoethanol undergoes carbonylation in pyridine solution in the presence of oxygen and of [Ni(CO)₃Pyl as a catalyst to give cyclic O, S-ethylelnethiorcarbonate. The isolation of thiolatonickel compound [Ni(SCH₂CH₂OH)₂] by the oxidation of a solution containing [Ni(CO)₃Py] and 2-mercaptoethanol, and its reaction with carbon monoxide to give the cyclic thiocarbonate and [Ni(CO)₃Py] prove that the reaction proceeds in at least two steps.     

Vibrational spectra of 1,2-diaminobenzene, 4,5-dimethyl-1,2-diaminobenzene and catechol and their SER spectra

The Raman and IR spectra of 1,2-diaminobenzene and 4,5-dimethyl-1,2-diaminobenzene are reported and assignments of fundamental modes proposed. The surface-enhanced Raman spectra (SERS) of catechol, 1,2-diaminobenzene and 4,5-dimethyl-1,2-diaminobenzene on gold and silver colloids were obtained. FT-SERS of the three molecules are also briefly reported.     

The stereoselective homolytic heterocyclization of disubstituted alkynes with 1,2-ethanedithiol to give cis-2,3-disubstituted 1,4-dithianes

Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1191–1192, May, 1990.     

Rotationally resolved electronic spectra of 1,2-dimethoxybenzene and the 1,2-dimethoxybenzene-water complex

Rotationally resolved S(1) <-- S(0) electronic spectra of 1,2-dimethoxybenzene (DMB) and its water complex have been observed and assigned. The derived values of the rotational constants show that the bare molecule has a planar heavy-atom structure with trans-disposed methoxy groups in its ground and excited electronic states. The transition of DMB is polarized along the b-axis bisecting the methoxy groups, demonstrating that its S(1) state is an (1)L(b) state. Higher energy bands of DMB are also polarized along the b-axis and have been tentatively assigned to different vibrational modes of the (1)L(b) state. The water complex origin appears 127 cm(-1) to the blue of the bare molecule origin. Analyses of the high resolution spectra of DMB/H(2)O and DMB/D(2)O suggest that the water molecule is attached via two O-H...O hydrogen bonds to the methoxy groups in both electronic states. A tunneling motion of the attached water molecule is revealed by a splitting of these spectra into two subbands. Potential barriers to this motion have been determined.     

Rydberg spectra of trans-1,2-dibromoethylene

(2+1) resonance-enhanced multiphoton ionization spectra of jet-cooled trans-1,2-dibromoethylene are reported for the first time. The two-photon spectral region between 149.7 and 141.2 nm was examined. A 4p(z)<--pi Rydberg transition between 66,800 and 68,000 cm(-1) with A(g) excited state symmetry was analyzed, as well as two 4f<--pi Rydberg transitions with B(g) excited state symmetry and one 4f<--pi Rydberg transition with A(g) excited state symmetry between 68,000 and 70,800 cm(-1). All Rydberg transitions observed in this work belong to series that converge to the first ionization potential of the molecule. The short vibrational progressions observed involve two totally symmetric in-plane normal modes: C=C-H bending (nu(3)) and C=C-Br bending (nu(5)) with average excited state frequencies of 829 and 226 cm(-1), respectively.     

Rate constants and vibrational distributions for water-forming reactions of OH and OD radicals with thioacetic acid, 1,2-ethanedithiol and tert-butanethiol

Reactions of OH and OD radicals with CH₃C(O)SH, HSCH₂CH₂SH, and (CH₃)₃CSH were studied at 298 K in a fast-flow reactor by infrared emission spectroscopy of the water product molecules. The rate constants (1.3 ± 0.2) × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ for the OD + CH₃C(O)SH reaction and (3.8 ± 0.7) × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹ for the OD + HSCH₂CH₂SH reaction were determined by comparing the HOD emission intensity to that from the OD reaction with H₂S, and this is the first measurement of these rate constants. In the same manner, using the OD + (C₂H₅)₂S reference reaction, the rate constant for the OD + (CH₃)₃CSH reaction was estimated to be (3.6 ± 0.7) × 10⁻¹¹ cm³ molecule⁻¹ s⁻¹. Vibrational distributions of the H₂O and HOD molecules from the title reactions are typical for H-atom abstraction reactions by OH radicals with release of about 50% of the available energy as vibrational energy to the water molecule in a 2:1 ratio of stretch and bend modes.