Structural patterns in inorganic and organoantimony derivatives of oxo- and thiodiorganophosphorus ligands

Base-Promoted Reactions of Organostibines with Alkynes and Organic Halides to Give Chalcogenated (Z)-Olefins and Ethers

Herein, with air-stable chalcogenated stibines (Sb-ER) as organometallic chalcogenating reagents, we developed base-promoted (Z)-hydrochalcogenation of alkynes with DMSO/DMSO-d₆ as hydrogen/deuterium sources, giving chalcogenated (Z)-olefins in good yields and with excellent regioselectivity. These reagents, easily synthesized from halostibines with in situ generated [Zn(ER)₂] at room temperature within a few minutes, could be also used in the base-promoted C(sp³)-S(Se) cross-coupling with C(sp³)-X and copper-catalyzed C(sp²)-S(Se) cross-coupling with C(sp²)-X (X = F, CI, Br, I) under mild conditions. This protocol could also be simply extended to organobismuth complexes (Bi-ER) with good functional tolerance.

Organophosphorus-selenium/tellurium reagents: from synthesis to applications

Organic selenium- and tellurium-phosphorus compounds have found wide application as reagents in synthetic inorganic and organic chemistry, such as oxygen/chalcogen exchange, oxidation/reduction, nucleophilic/electrophilic substitution, nucleophilic addition, free radical addition, Diels–Alder reaction, cycloadditions, coordination, and so on. This chapter covers the main classes of phosphorus-selenium/tellurium reagents, including binary phosphorus-selenium/tellurium species, organophosphorus(III)-selenium/tellurium compounds, phosphorus(V)-selenides/tellurides, diselenophosphinates/ditellurophopshinates, diselenaphosphetane diselenides, Woollins’ reagent, phosphorus-selenium/tellurium amides, and imides. Given the huge amount of literature up to mid-2017, this overview is inevitably selective and will focus particularly on their synthesis, reactivity, and applications in synthetic and coordination chemistry.

Establishing the correlation between catalytic performance and N→Sb donor–acceptor interaction: systematic assessment of azastibocine halide derivatives as water tolerant Lewis acids

A series of organoantimony(iii) halide complexes with a tetrahydrodibenzo[c,f][1,5]azastibocine framework were synthesized and employed as water tolerant Lewis acid catalysts.

Theoretical study of the gas-phase decomposition of Pb[(C6H5)2PSSe]2 single-source precursor for the chemical vapour deposition of binary and ternary lead chalcogenides

A theoretical study of Pb(II) square planar thioselenophosphinate, Pb[(C6H5)2PSSe]2 precursor for the chemical vapour deposition process of preparing lead chalcogenides, has been carried out. The geometries of the species were optimized by employing the density functional theory. The transition states as well as the linked intermediates linking them were confirmed with frequency analyses. The density functional theory calculation (M06/LACVP*, gas) reveals that kinetically, the steps that lead to PbSe formation are more favourable than those that lead to PbS and ternary PbSexS1−x formation on both the singlet and the doublet potential energy surface. However, thermodynamically, the steps that lead to ternary PbSexS1−x formation are more favourable than those that lead to PbSe and PbS formation on the doublet potential energy surface. On the singlet potential energy surface, an alternative route leading to the formation of ternary PbSexS1−x is more favoured on both thermodynamic and kinetic grounds than those that lead to PbSe and PbS formation. The computational studies indicate that the decomposition of the complex in chemical vapour deposition may involve more than one step, and thus the formation of ternary PbSexS1−x is a result of thermodynamic and kinetic factors in controlling the material formed during the deposition process.

Organoantimony and organobismuth complexes for CO2fixation

The utilization of organoantimony and organobismuth complexes in CO₂fixation is reviewed in this article.

The crystal and molecular structures of R2SnCl2(1,10-phenanthroline), R = iPr, Cy, CH2Ph and R2 = Me, Ph: a comparison between solid state and theoretical structures

The crystal and molecular structures of four diimine adducts formed between R2SnCl2 [R = iPr, Cy, CH2Ph; and R2 = Me, Ph] and 1,10-phenanthroline have been determined at room temperature. The colorless crystals of R = iPr are monoclinic, space group P21/c with unit cell dimensions a = 8.261(2) Å, b = 15.125(3) Å, c = 15.804(2) Å, β = 104.82(1), Z = 4 and D x = 1.586 Mg m−3. The yellow crystals of R = Cy are monoclinic, space group P21/n with unit cell dimensions a = 10.474(1) Å, b = 16.167(2) Å, c = 14.341(3) Å, β = 101.46(1)°, Z = 4 and D x = 1.496 Mg m−3. Orange crystals of R = CH2Ph are monoclinic, space group P21/n with unit cell dimensions a = 10.356(3) Å, b = 17.540(2) Å, c = 13.817(9) Å, β = 105.93(5)°, Z = 4 and D x = 1.519 Mg m−3. The colorless crystals of R2 = Me, Ph are monoclinic, space group P21/n with unit cell dimensions a = 9.118(2) Å, b = 11.023(2) Å, c = 18.712(2) Å, β = 93.03(1), Z = 4 and D x = 1.634 Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.045 using 2200 reflections for R = iPr; to R = 0.043 using 2644 reflections for R = Cy; to R = 0.045 using 2576 reflections for R = CH2Ph; and to final R = 0.036 for 2538 reflections for R2 = Me, Ph. The solid state structures of R2SnCl2(phen) feature distorted octahedral tin atom geometries with a trans disposition of the R substituents. A systematic trend to longer Sn–Cl and Sn–N distances with decreasing Lewis acidity is found, however, with a relatively large spread of values which is often correlated in the case of Sn–Cl with C1…H interactions. The structures of R2SnCl2(phen) have also been investigated employing ab initio methods at the Hartree-Fock SCF level of theory so that a correlation may be made between the R2SnCl2(phen) structures in the presence and absence of crystal packing effects. The calculated structures are generally more symmetric suggesting that there is no inherent chemical reason for a lack of symmetry in the solid state. Further, generally there is an elongation of Sn-ligand distances in the gas phase structures. These two key observations point to the importance of crystal packing effects on molecular geometry as well on the derived interatomic parameters.

Structural diversity in the mercury(II) bis(N,N-dialkyldithiocarbamate) compounds: an example of the importance of considering crystal structure when rationalising molecular structure

The crystal and molecular structures of four compounds of the general formula Hg(S2CNR2)2 are reported. The pale-yellow crystals of [Hg(S2CNiBu2)2] are monoclinic, space group C2/c with unit cell dimensions a = 26.27(2) Å, b = 13.654(8) Å, c = 13.863(5) Å, β = 96.64(4)°, Z = 8 and D x = 1.639 Mg m−3. The yellow crystals of [Hg(S2CN(iPr)Cy)2] are triclinic, space group P[unk] with unit cell dimensions a = 12.291(9) Å, b = 11.534(6) Å, c = 9.559(4) Å, α = 69.82(4)°, β = 88.94(4)°, γ = 72.00(5)°, Z = 2 and D x = 1.747 Mg m−3. Crystals of yellow [Hg(S2CN(Et)Cy)2] are monoclinic, space group P21/c with unit cell dimensions a = 8.459(6) Å, b = 19.506(9) Å, c = 13.955(6) Å, β = 92.89(4)°, Z = 4 and D x = 1.748 Mg m−3. The yellow crystals of [Hg(S2CNnBu2)2] are monoclinic, space group C2/c with unit cell dimensions a = 23.210(6) Å, b = 16.48(1) Å, c = 16.285(6) Å, β = 126.81(2)°, Z = 8 and D x = 1.623 Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.037 using 2994 reflections for [Hg(S2CNiBu2)2], to R = 0.043 using 3861 reflections for [Hg(S2CN(iPr)Cy)2]; to R = 0.041 for 2895 reflections for [Hg(S2CN(Et)Cy)2]; and to R = 0.065 for 2640 reflections for [Hg(S2CNnBu2)2]. A monomeric motif, featuring distorted tetrahedral geometries, is found for the structures of [Hg(S2CNiBu2)2] and [Hg(S2CN(iPr)Cy)2]. By contrast, dimeric structures, arising from the presence of bridging dithiocarbamate ligands, are found in the structures of [Hg(S2CN(Et)Cy)2] and [Hg(S2CNnBu2)2]. A critical examination of crystal structure for these and related systems enables a qualitative explanation for the structural diversity observed in the Hg(S2CNR2)2 compounds. The primary coordination about the mercury centers in Hg(S2CNR2)2 is linear and other associations, be they intra- or intermolecular, give rise to distortions from linearity and result in varied coordination geometries. The nature of the additional interactions is dictated by the need to maximise intermolecular associations.

Thus, when there are no steric restrictions precluding association in the lattice, Hg–S interactions are present that give rise to dimeric structures or 2-dimensional layer structures in the case when R = H.

Structural systematics of tellurium(II) bis(O-alkyldithiocarbonate) and tellurium(II) bis(N,N-dialkyldithiocarbamate) compounds

The crystal and molecular structures of three compounds, Te(S2COR)2, R = iBu and CH2Ph, and Te(S2CNCy2)2 have been determined at 200 K. The red crystals of [Te(S2COiBu)2] are monoclinic, space group P21/c with unit cell dimensions a = 15.535(10) Å, b = 10.402(4) Å, c = 10.832(4) Å, β = 109.43(5)°, Z = 4 and D x = 1.714 Mg m−3. The red crystals of [Te(S2COCH2Ph)2] are monoclinic, space group P21/n with unit cell dimensions a = 8.28(1) Å, b = 5.66(1) Å, c = 38.19(1) Å, β = 91.7(1)°, Z = 4 and D x = 1.834 Mg m−3. Crystals of red [Te(S2CNCy2)2] are monoclinic, space group P21/n with unit cell dimensions a = 9.417(3) Å, b = 27.11(1) Å, c = 11.745(3) Å, β = 102.10(2)°, Z = 4 and D x = 1.451 Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.035 using 2741 reflections for [Te(S2COiBu)2]; to R = 0.037 using 3062 reflections for(Te(S2COCH2Ph)2]; and to final R = 0.054 for 2722 reflections for [Te(S2CNCy2)2]. The tellurium atom in each of the structures exists in a trapezoidal planar geometry defined by four sulfur atoms derived from two asymmetrically coordinating 1,1-dithiolate ligands. Attempts to correlate the magnitude of the Te–S distances with the nature of R in the respective series of Te(S2COR)2 and Te(S2CNR2)2 compounds failed, nor was it possible to correlate Te–S with intermolecular Te ⋯ S interactions. Crystal packing forces are suggested to play a significant role in influencing the molecular parameters about the tellurium atoms in these systems.

The crystal and molecular structures of [Te(S2COR)2], R = nPr and CH2CH2CMe3

The crystal and molecular structures of bis(n-propyldithiocarbonato)tellurium (II), [Te(S2COnPr)2] (1), C8H14O2S4Te, and bis(3,3-dimethylbutyldithiocarbonato)tellurium(II), [Te(S2COCH2CH2CMe3)2] (2), C14H26O2S4Te, have been determined at room temperature. The red crystals of 1 are monoclinic, space group P21 with unit cell dimensions a = 10.501(6) Å, b = 5.973(3) Å, c = 12.055(1) Å, β = 102.39(2)°, Z = 2 and D x = 1.790Mg m−3. The red crystals of 2 are also monoclinic, space group P21/c with unit cell dimensions a = 16.744(6) Å, b = 6.098(4) Å, c = 21.334(3) Å, β = 104.89(2)°, Z = 4 and D x = 1.521Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.046 using 1314 reflections for 1 and to final R = 0.061 using 1194 reflections for 2. The molecular structures are similar and each feature two asymmetrically coordinating xanthate ligands that define a trapezoidal planar coordination geometry about the tellurium(II) center; the lone pairs of electrons are thought to lie over the weaker Te–S interactions. Each of the crystal structures is stabilised by supramolecular Te…S interactions.

An examination of the influence of crystal structure on molecular structure. The crystal and molecular structures of some diorganotinchloro-(N,N-dialkyldithiocarbamate)s, R2Sn(S2CNR′2)Cl, R = Me, tBu, Ph, Cy; R′2 = (Et)2, (Et, Cy) and (Cy)2: a comparison between solid state and theoretical structures

The crystal and molecular structures of five compounds of the general formula R2Sn(S2CNR′2)Cl have been determined at room temperature. The colorless crystals of [Me2Sn(S2CNEt2)Cl] are monoclinic, space group P21/c with unit cell dimensions a = 10.896(2) Å, b = 9.869(4) Å, c = 12.722(2) Å, β = 105.08(1)°, Z = 4 and D x = 1.672 Mg m−3. The colorless crystals of [Me2Sn(S2CNCy2)Cl] are monoclinic, space group P21/c with unit cell dimensions a = 6.758(6) Å, b = 19.046(3) Å, c = 15.190(5) Å, β = 98.09(4)°, Z = 4 and D x = 1.512 Mg m−3. Crystals of colorless [tBu2Sn(S2CN(Et)Cy)Cl] are monoclinic, space group P21/n with unit cell dimensions a = 13.481(5) Å, b = 11.466(5) Å, c = 15.351(8) Å, β = 107.51(4)°, Z = 4 and D x = 1.382 Mg m−3. The colorless crystals of [Cy2Sn(S2CNEt2)Cl] are monoclinic, space group P21/c with unit cell dimensions a = 17.107(6) Å, b = 11.134(2) Å, c = 11.953(6) Å, β = 104.00(3)°, Z = 4 and D x = 1.409 Mg m−3. The colorless crystals of [Cy2Sn(S2CNCy2)Cl] are monoclinic, space group P21/n with unit cell dimensions a = 11.411(7) Å, b = 16.942(5) Å, c = 14.712(5) Å, β = 100.45(3)°, Z = 4 and D x = 1.370 Mg m−3. The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.039 using 1367 reflections for [Me2Sn(S2CNEt2)Cl]; to R = 0.038 using 1881 reflections for [Me2Sn(S2CNCy2)Cl]; to R = 0.049 using 2707 reflections for [tBu2Sn(S2CN(Et)Cy)Cl]; to final R = 0.042 for 1914 reflections for [Cy2Sn(S2CNEt2)Cl]; and to final R = 0.045 for 2550 reflections for [Cy2Sn(S2CNCy2)Cl]. The crystallographic study shows that the tin atom in the R2Sn(S2CNR′2)Cl compounds exists in a distorted trigonal bipyramidal geometry in which the equatorial plane is defined by the two carbon atoms of the tin-bound organic substituents as well as more tightly held sulfur atom derived from an asymmetrically chelating dithiocarbamate ligand; the axial positions are defined by the less tightly held sulfur atom as well as the chloride atom. Attempts to correlate the Sn-ligand parameters with systematic variations in the Lewis acidity of the tin center (i.e. by moderating R) and the Lewis basicity of the dithiocarbamate ligand (i.e. by moderating R′) were unsuccessful across the series. The compounds have been subjected to geometry optimisation calculations which revealed that more symmetric structures exist in the gas phase. Systematic variations in the Sn-ligand parameters for the gas phase structures could be correlated with the Lewis basicity of the dithiocarbamate ligands in contrast to the solid state structures. Also, trends were found as the Lewis acidity of the tin center was varied. These trends could not, however, be correlated with the electronic structures of the tin-bound substituents alone, indicating that the steric profiles of the substituents also play an important role in moderating the Lewis acidity of the tin center. The results of the combined crystallographic/theoretical investigation of the R2Sn(S2CNR′2)Cl structures indicate that intermolecular forces, i.e. crystal packing effects, do exert a significant influence on the molecular geometry in these systems.

The crystal and molecular structures of R2Sn(O2CR1)Cl: R = Me, tBu and Ph; −O2CR1 = o-(2-hydroxy-5-methylphenylazo)benzoate

The crystal and molecular structures of three R2Sn(O2CR1)Cl compounds [R = Me, tBu and Ph; −O2CR1 = o-(2-hydroxy-5-methylphenylazo)benzoate] have been determined at room temperature. Brown crystals of Me2Sn(O2CR1)Cl (1), C16H17ClN2O3Sn, are triclinic, space group P[unk] with unit cell dimensions a = 10.649(4) Å, b = 12.292(3) Å, c = 7.236(2) Å, α = 96.68(3)°, β = 104.03(3)°, γ = 109.12(3)°, Z = 2 and Dx = 1.662 Mg m−3. Red crystals of tBu2Sn(O2CR1)Cl (2), C22H29ClN2O3Sn, are monoclinic space group P21/n with unit cell dimensions a = 8.323(5) Å, b = 24.990(5) Å, c = 12.403(5) Å, β = 107.94(3)°, Z = 4 and Dx = 1.417 Mg m−3. Red crystals of Ph2Sn(O2CR1)Cl (3), C26H21ClN2O3Sn, are also monoclinic with space group P21/c and unit cell dimensions a = 14.416(3) Å, b = 16.373(6) Å, c = 10.489(4) Å, β = 97.10(3)°, Z = 4 and Dx = 1.524 Mg m−3 The structures were solved by Patterson (1 and 2) or direct methods (3) and each refined by a full-matrix least-squares procedure to final R = 0.039 using 2933 reflections for 1, R = 0.039 for 2935 reflections for 2, and R = 0.037 using 2863 reflections for 3. The structure of 1 is dimeric with the two tin atoms being bridged by two −O2CR1 anions each of which coordinates a tin atom via one of the carboxylate oxygen atom and the second tin atom via the phenoxide oxygen atom; this result indicates that the −O2CR1 anion exists as a Zwitterion. The tin atom geometry is trigonal bipyramidal. trans-O2SnC2Cl. By contrast to the dimeric structure for 1, the structures of 2 and 3 are monomeric with the tin atoms in cis-O2SnC2Cl trigonal bipyramidal geometries. The −O2CR1 anion coordinates the tin atom in each of 2 and 3 via the carboxylate oxygen atoms only.

The crystal and molecular structures of A(S2COCH2CH2CMe3)3, A = As(III), Sb(III) and Bi(III)

The crystal and molecular structures of tris(3,3-dimethylbutyldithiocarbonato)-arsenic(III), -antimony(III) and -bismuth(III), A(S2COCH2CH2CMe3)3, have been determined at room temperature. The colorless crystals of A = As(III) are triclinic, space group P[unk] with unit cell dimensions a = 11.837(2) Å, b = 13.430(2) Å, c = 10.284(1) Å, α = 98.39(1)°, β = 102.472(9)°, γ = 101.73(1)°, Z = 2 and D x = 1.316 Mg m−3. The colorless crystals of A = Sb(III) are monoclinic, space group P21/c with unit cell dimensions a = 16.110(3) Å, b = 6.077(4) Å, c = 31.101(3) Å, β = 97.65(1)°, Z = 4 and D x = 1.439 Mg m−3. The yellow crystals of A = Bi(III) are also monoclinic, space group P21/c with unit cell dimensions a = 16.149(3) Å, b = 6.063(3) Å, c = 31.052(7) Å, β = 97.25(2)°, Z = 4 and D x = 1.632 Mg m−3 The structures were solved by direct methods and each refined by a full-matrix least-squares procedure to final R = 0.042 using 3118 reflections for A = As(III); to R = 0.051 using 3357 reflections for A = Sb(III); and to final R = 0.056 for 2606 reflections for A = Bi(III). The A = As(III) structure comprises isolated molecules with the central atom existing in a distorted capped octahedral geometry. A disorted pentagonal bipyramidal geometry is found in the A = Sb(III) structure where loose association, via Sb … S interactions, are found between centrosymmetrically related pairs. An analogous structure is found for A = Bi (III), however, relatively stronger Bi … S interactions are in existence. A discussion of the different motifs found for A(S2COR)3 structures indicates the importance of crystal packing effects, i.e. the desire to maximise A … S intermolecular contacts, in these structures.

Examination of the effect of crystal packing forces on geometric parameters: a combined crystallographic and theoretical study of 2,2'-bipyridyl adducts of R2SnCl2

Crystal structure determinations on a series of R2SnCl2(bipy)[bipy is 2,2'-bipyridyl] compounds show that these adopt a common structural motif in the solid-state with the Sn-bound organic substituents occupying mutually trans positions in a distorted octahedral geometry. A comparison of the experimental Sn–Cl and Sn–N bond distances with the moderated (i.e. by changing the nature of R) Lewis acidities of the tin atoms shows a general correlation, i.e. longer distances with decreasing Lewis acidity, but with a relatively large spread of values. In order to examine the role of crystal packing effects on the derived geometric parameters, gas-phase structures for these compounds have been modeled employing ab initio molecular orbital theory. These calculations showed that within individual compounds the two Sn–Cl distances are equal as are the two Sn–N distances, in contrast to the solid-state results. Further, a better correlation between the Sn–Cl and Sn–N bond distances and the Lewis acidity of the tin atom was found. These key results are attributed to the influence of crystal packing forces on the geometric parameters about the tin center in the solid-state.