The preparation of cobalt complexes containing simple sulphur-nitrogen ligands,S2N2H− and S3N−, from S4N4O2

Summary Reactions of Group VIII metal halides [CoCl₂, NiCl₂, K₂PdCl₄, PdCl₂(PhCN)₂ and PtCl₂] with tetrasulphurtetranitrogendioxide, S₄N₄O₂, have been investigated. The cobalt reaction yields Co(S₂N₂H)₂, Co(S₂N₂H)(S₃N) and Co(S₃N)₂. The usefulness of metal centres for trapping reactive sulphur-nitrogen centres is discussed.     

Highly Strained Heterocycles Constructed from Boron–Boron Multiple Bonds and Heavy Chalcogens

The reactions of a diborene with elemental selenium or tellurium are shown to afford a diboraselenirane or diboratellurirane, respectively. These reactions are reminiscent of the sequestration of subvalent oxygen and nitrogen in the formation of oxiranes and aziridines; however, such reactivity is not known between alkenes and the heavy chalcogens. Although carbon is too electronegative to affect the reduction of elements with lower relative electronegativity, the highly reducing nature of the B?B double bond enables reactions with Se⁰ and Te⁰. The capacity of multiple bonds between boron atoms to donate electron density is highlighted in reactions where diborynes behave as nucleophiles, attacking one of the two Te atoms of diaryltellurides, forming salts consisting of diboratellurenium cations and aryltelluride anions.     

Synthesis and structure of novel [Ph(RO)PSe2]- complexes

Reaction of (PhPSe2)2(Woollins reagent) with NaOR (R = Me, Et, (i)Pr) gives the non-symmetric phosphonodiselenoato anions [Ph(RO)PSe2]- which can be complexed to a range of metals. The nickel complex Ni[Ph(MeO)PSe2]2 adopts a square-planar ML2 structure while the cadmium complex Cd[Ph(MeO)PSe2]2 displays a dimeric M2L4 structure. Two different lead complexes are observed, one consisting of PbL2 units joined by Pb...Se interactions to form distinct dimeric pairs. The other displays a novel dimeric structure built around a central four-membered Pb2Se2 ring. All new compounds have been characterised spectroscopically (31P, 1H, 13C NMR, IR, mass spectroscopy), by elemental analysis and five demonstrative X-ray structures are reported.     

Heterocycles from Diferrocenyl Dithiadiphosphetane Disulfide

Diferrocenyl dithiadiphosphetane disulfide (Fc₂P₂S₄) had been found act as a source of a reactive species, believed to be FcPS₂, which reacts with dialkyl cyanamides, imines, aldehydes and strained alkenes to form a variety of phosphorus compounds. These reactions include a convenient route to thiaphosphetanes.     

Rhodium(I) carbonyl complexes of chalcogen functionalized tripodal phosphines, [CH3C(CH2P(X)Ph2)3] {X = O, S, Se} and their reactivity

The reaction of dimeric rhodium precursor [Rh(CO)₂Cl]₂ with two molar equivalent of 1,1,1-tris(diphenylphosphinomethyl)ethane trichalcogenide ligands, [CH₃C(CH₂P(X)Ph₂)₃](L), where X = O(a), S(b) and Se(c) affords the complexes of the type [Rh(CO)₂Cl(L)] (1a–1c). The complexes 1a–1c have been characterized by elemental analyses, mass spectrometry, IR and NMR (¹H, ³¹P and ¹³C) spectroscopy and the ligands a–c are structurally determined by single crystal X-ray diffraction. 1a–1c undergo oxidative addition (OA) reactions with different electrophiles such as CH₃I, C₂H₅I and C₆H₅CH₂Cl to give Rh(III) complexes of the types [Rh(CO)(COR)ClXL] {R = –CH₃ (2a–2c), –C₂H₅ (3a–3c); X = I and R = –CH₂C₆H₅ (4a–4c); X = Cl}. Kinetic data for the reaction of a–c with CH₃I indicate a first-order reaction. The catalytic activity of 1a–1c for the carbonylation of methanol to acetic acid and its ester is evaluated and a higher turn over number (TON = 1564–1723) is obtained compared to that of the well-known commercial species [Rh(CO)₂I₂]⁻ (TON = 1000) under the reaction conditions: temperature 130 ± 2 °C, pressure 30 ± 2 bar and time 1 h.     

Preparation and compounds of (8-methoxynaphth-1-yl)diphenylphosphine

Reaction of 8-methoxy-1-naphthyllithium (2) with one equivalent of chlorodiphenylphosphine gives the novel (8-methoxynaphth-1-yl)diphenylphosphine (3) which was oxidised to the corresponding sulfide (4) and selenide (5) by reaction with sulfur and selenium, respectively. The P?O peri distance is significantly increased in 4 and 5 at 2.819(3) [2.793(3)] and 2.827(3) [2.806(3)] ? [values in square brackets are for the second independent molecules in each case] relative to the value in 3 of 2.678(2) Å. There are short E?O interactions ie O(1)?S(1) 3.165(3) [3.124(3)], O(1)?Se(1) 3.247(3) [3.200(2)] ? and these may be repulsive and responsible for the increased P?O separation. The use of the naphthalene backbone in the synthesis of a potential hemilabile ligand is demonstrated by the synthesis and X-ray structure of (8-methoxynaphth-1-yl)diethoxyphosphine ruthenium p-cymene dichloride (6).     

The X-ray Structures of Sulfones

Abstract  

The X-rays structures of diphenyl sulfone 1, bis(3-aminophenyl) sulfone 2, bis(4-nitrophenyl) sulfone 3, 2-nitrophenylphenyl sulfone 4, benzylphenzyl sulfone 5, 4-nitrobenzylphenyl sulfone 6, 4-methylphenylbenzyl sulfone 7, dibenzyl sulfone 8, benzylisopropyl sulfone 9, and methylacetate,ethyl sulfone 10, are reported. B3PW91 DFT calculations were performed on selected sulfones for comparison. The S = O distances in these compounds range from 1.392(5) to 1.463(3) Å and S–C bond distances range from 1.743(7) to 1.790(3) Å. The C–S–C bond angles vary from 101.1(3)° to 106.80(14)° and the O–S–O bond angles vary from 116.7(2)° to 120.61(8)°. Using data obtained here and comparison with published structural data no evidence was found for para substituents on aryl groups influencing S–O bond distances, however, small changes on S–C bond distances were noted. Additionally, if the sulfur is flanked by an alkyl group the S–C distance is slightly larger than when it is flanked by an aryl group. Most of the sulfone compounds studied here display intermolecular soft hydrogen bonding interactions which influence their solid state packing. Furthermore, in dialkyl sulfone compounds these interactions appear to be strong enough to overcome conformational barriers calculated to be ca. 6 kJ mol⁻¹.