Weak Sn Research Articles

Is the Presence of Sn2+ a Crucial Factor for the Generation of Low Thermal Conductivity in Tin-Based Sulfides?

Comprehending the relationship between crystal structures and transport properties is crucial to develop materials with improved electrical and thermal properties for thermoelectric applications. In this article, we report on the complex crystal structure and physical properties of Cr2Sn3S7, a n-type magnetic semiconductor with a low energy band gap and low thermal conductivity. Importantly, we demonstrate that the high level of structural complexity is related to the coexistence of two sublattices: a host lattice, [Cr4Sn2S11]2-, characterized by a mixed Sn4+/Cr3+ occupancy of its cationic sites, and a guest lattice characterized by [Sn4S3]2+ chains, containing Sn2+ cations only, closely related to the ones encountered in the orthorhombic SnS compound. By combining experiments including X-ray diffraction with ab initio calculations of electrons and phonons, we succeeded to elucidate the origin of the low thermal conductivity in Cr2Sn3S7. We demonstrate that the low dimensionality of the [Sn4S3]2+ chains, which generates weak Sn···S interactions with the 3D host lattice, is induced by the lone pair stereochemical activity of Sn2+. This lattice softening favors strong anisotropic vibrations at low frequencies, highlighting the primordial role played by Sn2+ cations in both crystal structure dimensionality and low thermal conductivity in tin-based sulfides.

Synthesis of organotin(IV) heterocycles containing a xanthenyl group by a Barbier approach via ultrasound activation: synthesis, crystal structure and Hirshfeld surface analysis.

A series of organotin heterocycles of general formula [{Me2C(C6H3CH2)2O}SnR2] [R= methyl (Me, 4), n-butyl (n-Bu, 5), benzyl (Bn, 6) and phenyl (Ph, 7)] was easily synthesized by a Barbier-type reaction assisted by the sonochemical activation of metallic magnesium. The 119Sn{1H} NMR data for all four compounds confirm the presence of a central Sn atom in a four-coordinated environment in solution. Single-crystal X-ray diffraction studies for 17,17-dimethyl-7,7-diphenyl-15-oxa-7-stannatetracyclo[11.3.1.05,16.09,14]heptadeca-1,3,5(16),9(14),10,12-hexaene, [Sn(C6H5)2(C17H16O)], 7, at 100 and 295 K confirmed the formation of a mononuclear eight-membered heterocycle, with a conformation depicted as boat-chair, resulting in a weak Sn...O interaction. The Sn and O atoms are surrounded by hydrophobic C-H bonds. A Hirshfeld surface analysis of 7 showed that the eight-membered heterocycles are linked by weak C-H...π, π-π and H...H noncovalent interactions. The pairwise interaction energies showed that the cohesion between the heterocycles are mainly due to dispersion forces.

Depth profile CF LIBS analysis of the wall deposited layer in the COMPASS tokamak after LiSn testing campaign

Plasma-facing materials in tokamak nuclear reactors are subject to intense heat and radiation. The design of liquid metal (LM) divertor walls has several advantages over the solid counterparts. It is important to understand the migration and re-deposition of LMs such as lithium (Li), lead (Pb) or even tin (Sn). This work presents CF LIBS depth profile analysis of the deposited layer on Ni–Cr based screws situated at different places in the COMPASS tokamak vessel during the Capillary Porous System (CPS) LM (LiSn) divertor testing campaign. The experiment was carried out at low Ar pressure (100 mbar) using ns Nd:YAG laser operating at 532 nm. The spectra were recorded using echelle spectrometer (M5000, Andor Tech.) equipped with an iCCD camera (iStar DH743, Andor Tech.). The quantification was based on observed C I, B I, Li I and (weak) Sn I lines, in addition to trace elements (Ca, Na, K) and main matrix elements (Cr, Ni, Fe). The evaluation of electron temperature and density was based on Cr I-II, Ni-II and Fe I-II lines. The LM based content is estimated to be Li (0.3-0.81 at.%) and Sn (0.1-0.23 at.%) with Li/Sn at.% ratio ranging from 3 to 3.5 (wt.% ratio of 0.17-0.20). In practise, the limit of detection of Sn by CF LIBS for this type of Cr-Ni-Fe based matrix is observed to be ∼0.1 at.%.

Formation and structural characterization of the basic tin(II) fluoride, Sn9F13O(OH)3 ⋅ 2H2O, containing the unprecedented [Sn4O(OH)3]3+ cage‐ion

AbstractSingle crystals of the title compound Sn9F13O(OH)3 ⋅ 2H2O, 3, along with those of the oxofluoride Sn4OF6, 2, and the fluorophosphate Sn3(PO4)F3, 1, have been obtained in course of an experiment mimicking the reaction of the tooth paste additive SnF2 with Ca3(PO4)2 as dentin surrogate. All three compounds have been characterized by single crystal X‐ray diffraction. While our data on the crystal structures 1 and 2 confirm previous results but improve bond lengths and angles precision significantly, 3 represents the first example of a basic tin(II) fluoride the structure of which was determined. Its crystal structure consists of bilayers held together through weak secondary Sn⋅⋅⋅F‐bonds while their unsymmetrical, protic‐aprotic monolayers are connected with each other on their protic sites via −OH⋅⋅⋅F‐hydrogen bonds. The most prominent building block of the monolayers constitutes the unprecedented, stella octangula like [Sn4O(OH)3]3+ cage‐ion. The coordination spheres of all nine Sn(II) atoms are analyzed with respect to their constitution, geometry and bonding. The observed bond lengths and bond angles of the tin(II) atoms are interpretated in terms of p‐p‐bonding via 2e–2c bonds (first coordination sphere, {SnX3}, trigonal‐pyramidal) and 4e–3c‐bonds (second coordination sphere, {SnX4}/{SnX5}, seesaw/square‐pyramidal). Bond valence calculations have been found to be of limited benefit to predict the oxidation state of Sn(II) especially when Sn−O bonds are present.

Exceedingly High Performance Top-Gate P-Type SnO Thin Film Transistor with a Nanometer Scale Channel Layer.

Implementing high-performance n- and p-type thin-film transistors (TFTs) for monolithic three-dimensional (3D) integrated circuit (IC) and low-DC-power display is crucial. To achieve these goals, a top-gate transistor is preferred to a conventional bottom-gate structure. However, achieving high-performance top-gate p-TFT with good hole field-effect mobility (μFE) and large on-current/off-current (ION/IOFF) is challenging. In this report, coplanar top-gate nanosheet SnO p-TFT with high μFE of 4.4 cm2/Vs, large ION/IOFF of 1.2 × 105, and sharp transistor’s turn-on subthreshold slopes (SS) of 526 mV/decade were achieved simultaneously. Secondary ion mass spectrometry analysis revealed that the excellent device integrity was strongly related to process temperature, because the HfO2/SnO interface and related μFE were degraded by Sn and Hf inter-diffusion at an elevated temperature due to weak Sn–O bond enthalpy. Oxygen content during process is also crucial because the hole-conductive p-type SnO channel is oxidized into oxygen-rich n-type SnO2 to demote the device performance. The hole μFE, ION/IOFF, and SS values obtained in this study are the best-reported data to date for top-gate p-TFT device, thus facilitating the development of monolithic 3D ICs on the backend dielectric of IC chips.

11.5% efficient Cu2ZnSn(S,Se)4 solar cell fabricated from DMF molecular solution

The weak Sn–O coordination bonds in Sn(DMF)2Cl4 result in the formation of a kesterite phased (Cu2ZnSnS4) precursor film and thus fabrication of a highly efficient Cu2ZnSn(S,Se)4 absorber from DMF solution.

Lithiation-induced interfacial failure of electrode-collector: A first-principles study

Abstract By using first-principles calculations, we investigate the interfacial failure between a lithiated Sn electrode and a Cu current collector for lithium-ion batteries. The results show that segregation of Li ions at the interfacial region leads to the transformation of interfacial bonding from Sn‒Cu to Li‒Cu bonds, and weak Li‒Sn bonds near the interface region. This leads to the weakened interfacial strength upon lithiation and failure of most lithiated Sn/Cu interfaces within LixSn slabs. In addition, the formation of CuxSn alloys at interface could increase the interface strength and enhance the deformation resistance of electrode materials, which explains why CuxSn containing composite electrodes exhibits the excellent electrochemical performance.

Topological surface Fermi arcs in the magnetic Weyl semimetal Co3Sn2S2

Very recently, the half-metallic compound Co$_3$Sn$_2$S$_2$ was predicted to be a magnetic WSM with Weyl points only 60 meV above the Fermi level ($E_F$). Owing to the low charge carrier density and large Berry curvature induced,Co$_3$Sn$_2$S$_2$ possesses both a large anomalous Hall conductivity (AHC) and a large anomalous Hall angle (AHA), which provide strong evidence for the existence of Weyl points in Co$_3$Sn$_2$S$_2$. In this work, we theoretically studied the surface topological feature of Co$_3$Sn$_2$S$_2$ and its counterpart Co$_3$Sn$_2$Se$_2$. By cleaving the sample at the weak Sn--S/Se bonds, one can achieve two different surfaces terminated with Sn and S/Se atoms, respectively. The resulting Fermi arc related states can range from the energy of the Weyl points to $E_F$--0.1 eV in the Sn-terminated surface. Therefore, it should be possible to observe the Fermi arcs in angle-resolved photoemission spectroscopy (ARPES) measurements. Furthermore, in order to simulate quasiparticle interference (QPI) in scanning tunneling microscopy (STM) measurements, we also calculated the joint density of states (JDOS) for both terminals. This work would be helpful for a comprehensive understanding of the topological properties of these two magnetic WSMs and further ARPES and STM measurements.

Bis(μ-benzoato-κ2O:O')bis-(benzoato-κO)octabutyldi-μ3-oxido-tetra-tin(IV).

The asymmetric unit of the title compound, [{Sn(C4H9)2(C6H5COO)}2O]2, consists of two half molecules, completed by application of inversion symmetry. Both mol-ecules adopt a ladder structure typical for this class of dimeric tetra-organodistannoxane di-carboxyl-ates characterized by a centrosymmetric four-membered (Sn-O)2 ring of rhomboidal shape that is extended on both sides by folded six-membered Sn-O-C rings. To a first approximation, both kinds of Sn atoms (Sn i and Sn o ) are trigonal-bipyramidally coordinated. The bond angles between the n-butyl groups are widened [135.64 (7)-146.20 (7)°] in comparison with an ideal trigonal bipyramid. Sn-O bond lengths within the {R2SnO3} coordination sphere depend strongly on the position of the corresponding O atom - axial (ax) or equatorial (eq) - as well as on the functionality of the carboxyl-ate groups which exhibit μ2 (-COO i ) and μ1 (-COO o ) coordination modes, respectively. In summary, the following sequence of distances [mean values] is found: d(Sn o -Oμ3) eq [2.024 (2) Å] < d(Sn i -Oμ3) eq [2.044 (2) Å] < d(Sn i -Oμ3) ax [2.158 (6) Å] < d(Sn o -Oμ1-carb) ax [2.182 (6) Å] < d(Sn i -Oμ2-carb) ax [2.250 (2) Å] ≃ d(Sn o -Oμ2-carb) ax [2.247 (12) Å]. The n-butyl groups adopt an anti-anti conformation with exception of two disordered outer n-butyl groups of the second mol-ecule which exhibit gauche-anti and anti-gauche conformations. Weak intra-molecular Sn⋯O inter-actions between the different O atoms of the outer carboxyl groups with the inner, as well as outer, Sn atoms give rise to a strongly distorted octa-hedral coordination at these Sn atoms. Inter-molecular inter-actions between the individual mol-ecules are restricted to van der Waals and O⋯H-C inter-actions of which a nearly linear very short C-H⋯O contact between the H atom of the phenyl group of one of the mol-ecules with the outer non-coordinating C=O group of the other molecule is the most prominent. It gives rise to a chain-like arrangement of the mol-ecules along [111]. The two n-butyl groups attached to the outer Sn atom of one mol-ecule are disordered over two sets of sites with occupancies of 0.806 (3)/0.194 (3) and 0.702 (3)/0.298 (3).

Unbounded composition operators via inductive limits: Cosubnormal operators with matrix symbols, II

This article deals with unbounded composition operators with infinite matrix symbols acting in L2-spaces with respect to the Gaussian measure on R∞. We introduce weak cohyponormality classes Sn,r∗ of unbounded operators and provide criteria for the aforementioned composition operators to belong to Sn,r∗. Our approach is based on inductive limits of operators.

π–π Stacking motifs in dialkylbis{5-[(E)-2-aryldiazen-1-yl] 2-hydroxybenzoato}tin(IV) complexes

The diorganotin(IV) complexes of 5-[(E)-2-aryl­diazen-1-yl]-2-hy­droxy­benzoic acid are of inter­est because of their structural diversity in the crystalline state and their inter­esting biological activity. The structures of di­methyl­bis­{2-hy­droxy-5-[(E)-2-(4-methyl­phen­yl)diazen-1-yl]­benzoato}tin(IV), [Sn(CH3)2(C14H11N2O3)2], and di-n-butyl­bis­{2-hy­droxy-5-[(E)-2-(4-methyl­phen­yl)diazen-1-yl]­ben­zo­ato}tin(IV) benzene hemisolvate, [Sn(C4H9)2(C14H11N2O3)2]·0.5C6H6, exhibit the usual skew-trapezoidal bipyramidal coordination geometry observed for related complexes of this class. Each structure has two independent mol­ecules of the SnIV complex in the asymmetric unit. In the di­methyl­tin structure, inter­molecular O—H⋯O hydrogen bonds and a very weak Sn⋯O inter­action link the independent mol­ecules into dimers. The planar carboxyl­ate ligands lend themselves to π–π stacking inter­actions and the diversity of supra­molecular structural motifs formed by these inter­actions has been examined in detail for these two structures and four closely related analogues. While there are some recurring basic motifs amongst the observed stacking arrangements, such as dimers and step-like chains, variations through longi­tudinal slipping and inversion of the direction of the overlay add complexity. The π–π stacking motifs in the two title complexes are combinations of some of those observed in the other structures and are the most complex of the structures examined.

Crystal structure of bis-(benzoato-κO)di-butyl-tin(IV), nBu2Sn(bzo)2.

The title compound, [Sn(C4H9)2(C6H5COO)2], was synthesized in order to study the inter-action between di-n-butyl-tin(IV) oxide and some carb-oxy-lic acids. Di-n-butyl-tin(IV) dibenzoate, nBu2Sn(obz)2, exhibits the same structural features as other diorganotin(IV) dibenzoates characterized by an unsymmetrical bidentate bonding mode [Δ(Sn-O) ≃ 0.4 Å] of the two benzoate groups to tin. In a first approximation, the coordination sphere at tin resulting from the two stronger bonded O atoms [2.1227 (17) and 2.1405 (16) Å] and the two α-C atoms of the n-butyl groups [2.125 (3) and 2.129 (2) Å] is compressed to a tetra-gonal disphenoid [〈(C-Sn-C) = 148.2 (1)° and 〈(O-Sn-O) = 82.01 (6)°]. This coordination sphere is expanded by the less strongly bonded two O atoms [2.507 (2) and 2.485 (2) Å] to a substanti-ally distorted octa-hedron and by a weak inter-molecular Sn⋯O inter-action [2.943 (2) Å] to a penta-gonal bipyramid with the formation of centrosymmetric dimers. The unbranched butyl groups adopt two different conformations: anti-gauche [torsion angles: 166.0 (2)-63.9 (4)°] and gauche-gauche [65.0 (3)-56.3 (3)°]. Inter-molecular inter-actions between the dimers are restricted to O⋯H-C contacts (2.64 Å) and van der Waals inter-actions.

Evaluation of WRF model simulations of tropical cyclones in the western North Pacific over the CORDEX East Asia domain

In this study, the characteristics of tropical cyclones (TCs) over the East Asia Coordinated Regional Downscaling Experiment domain are examined with the Weather Research and Forecasting (WRF) model. Eight 20-year (1989–2008) simulations are performed using the WRF model, with lateral boundary forcing from the ERA-Interim reanalysis, to test the sensitivity of TC simulation to interior spectral nudging (SN, including nudging time interval, nudging variables) and radiation schemes [Community Atmosphere Model (CAM), Rapid Radiative Transfer Model (RRTM)]. The simulated TCs are compared with the observation from the Regional Specialized Meteorological Centers TC best tracks. It is found that all WRF runs can simulate the climatology of key TC features such as the tracks and location/frequency of genesis reasonably well, and reproduce the inter-annual variations and seasonal cycle of TC counts. The SN runs produce enhanced TC activity compare to the runs without SN. The thermodynamic profile suggests that nudging with horizontal wind increases the unstable of thermodynamic states in tropics, which results in excessive TCs genesis. The experiments with wind and temperature nudging improve the overestimation of TCs numbers, especially suppress the TCs intensification by correct the thermodynamic profile. Weak SN coefficient enhances TCs activity significantly even with wind and temperature nudging. The analysis of TCs numbers and large scale circulation shows that the SN parameters adopted in our experiments do not appear to suppress the formation of TC. The excessive TCs activity in CAM runs relative to RRTM runs are also due to the enhanced atmospheric instability.

π-π stacking motifs in dialkylbis{5-[(E)-2-aryldiazen-1-yl]-2-hydroxybenzoato}tin(IV) complexes.

The diorganotin(IV) complexes of 5-[(E)-2-aryldiazen-1-yl]-2-hydroxybenzoic acid are of interest because of their structural diversity in the crystalline state and their interesting biological activity. The structures of dimethylbis{2-hydroxy-5-[(E)-2-(4-methylphenyl)diazen-1-yl]benzoato}tin(IV), [Sn(CH3)2(C14H11N2O3)2], and di-n-butylbis{2-hydroxy-5-[(E)-2-(4-methylphenyl)diazen-1-yl]benzoato}tin(IV) benzene hemisolvate, [Sn(C4H9)2(C14H11N2O3)2]·0.5C6H6, exhibit the usual skew-trapezoidal bipyramidal coordination geometry observed for related complexes of this class. Each structure has two independent molecules of the Sn(IV) complex in the asymmetric unit. In the dimethyltin structure, intermolecular O-H...O hydrogen bonds and a very weak Sn...O interaction link the independent molecules into dimers. The planar carboxylate ligands lend themselves to π-π stacking interactions and the diversity of supramolecular structural motifs formed by these interactions has been examined in detail for these two structures and four closely related analogues. While there are some recurring basic motifs amongst the observed stacking arrangements, such as dimers and step-like chains, variations through longitudinal slipping and inversion of the direction of the overlay add complexity. The π-π stacking motifs in the two title complexes are combinations of some of those observed in the other structures and are the most complex of the structures examined.

Point-contact spectroscopy of electron-phonon interaction in superconductors

The possibility to reconstruct the electron-phonon interaction (EPI) function was demonstrated for S–c–N and S–c–S point contacts using the superconducting inelastic contribution to the excess current caused by Andreev reflection processes. Superconductors with both weak (Sn, Al) and strong (Pb, In) EPI were considered. It was shown that in the latter case it is necessary to account for the elastic component of current which is related to the frequency dependence of the superconducting energy gap arising due to electron-phonon renormalization of the energy spectrum of the superconductor.

Synthesis, structural characterization, in vitro cytotoxicities, DNA-binding and BSA interaction of diorganotin (IV) complexes derived from hydrazone Schiff base

Five diorganotin(IV) complexes of benzoylformic acid 3-hydroxy-2-naphthoyl hydrazone, [R2SnLY]2 (L = 3-HO-C10H6CON2C(C6H5)CO2) with Y=H2O, R = CH3 (1), Y = EtOH, R = Ph (3), Y = EtOH, R = o-Cl-Bz (4), Y = EtOH, R = o-F-Bz (5), and [R2SnLY] with Y = EtOH, R = n-Bu (2) were prepared, which were structurally characterized by X-ray crystallography, elemental, IR and NMR (1H and 13C ) spectroscopy. Structural analysis reveal that the ligand presents as tridentate ligand with ONO donors and coordinates to the tin center in an enolic form. Compound 2 is a monomer while the other compounds are weakly bridged dimers with weak Sn⋯O interactions. In vitro cytotoxicities of compounds 1, 3 and the ligand were determined to explore their potential anticancer activities. DNA-binding properties of 1 and 3 with calf thymus DNA (ct-DNA) were investigated by fluorescence quenching method with ethidium bromide (abbr. EB)-DNA system. Furthermore, the protein fluorescence quenching studies reveal that there are strong binding interactions between compounds 1, 3 and bovine serum albumins (BSA). Synchronous fluorescence spectra show that both the tryptophan and tyrosine residues in BSA are affected by the two compounds.

Dinuclear organotin(IV) complexes with bis-acyl-hydrazones containing flexible linker: Synthesis, spectroscopic investigation and crystal structure of dimethyl- and diphenyltin(IV) complexes with succinic dihydrazones

Four new dinuclear organotin(IV) complexes, (R2Sn)2La [R = Me (1), R = Ph (2)] and (R2Sn)2Lb [R = Me (3), R = Ph (4)], have been synthesized from the reaction of R2SnCl2 (R = Me or Ph) with bis(2-hydroxy-3-methoxybenzylidene)succinohydrazide (H4La) and bis(5-bromo-2-hydroxybenzylidene)succinohydrazide (H4Lb). The synthesized compounds have been investigated by elemental analysis, IR, 1H NMR, 13C NMR and 119Sn NMR spectroscopy. The results show the all complexes are dinuclear and two doubly deprotonated tridentate domain of the acyldihydrazone is coordinated to two SnR2 moieties via phenolic oxygen, imine nitrogen and enolic oxygen. The structures of 1 and 3 have been also confirmed by X-ray crystallography. Both complexes are centrosymmetry with the alkyl linker chain shows anti conformation. The intermolecular weak Sn⋯O bonds lead to 1D polymeric chain containing four-membered Sn2O2 planar rings. On the basis of 119Sn NMR data coordination number of tin is five in solution.

Synthesis, structural characterization and antimicrobial activity of mixed aryl–alkyl diorganotin(IV) compounds with quinoline‐2‐carboxylate (L−): {RR′SnLCl}n and RR′SnL2

A series of unsymmetrical diorganotin derivatives of quinoline‐2‐carboxylic acid (LH), namely polymeric {MePhSnClL}n (1) and {EtPhSnClL}n (2), and mononuclear MePhSnL2 (3) and EtPhSnL2 (4), was synthesized by the reaction of LH with the MePhSnCl2, EtPhSnCl2, MePhSnO, and EtPhSnO precursors, respectively. The compounds were characterized by elemental analysis and infrared spectroscopy, as well as by 1 H, 13 C and 119Sn NMR. The molecular structures of representative compounds 2 and 4 were determined by single‐crystal X‐ray crystallography. This study showed that polymeric 2 adopts a distorted octahedral geometry as the carboxylate ligand N,O chelates an Sn atom and at the same time bridges a neighbouring Sn atom via the second O atom, with the remaining sites being occupied by the Cl and two C atoms; the O atoms are trans to each other. The result of the μ2‐bridging mode of L− is the formation of a supramolecular helical chain. Compound 4 adopts a skew‐trapezoidal bipyramidal geometry with the organo groups lying over the plane of the two N,O‐chelating carboxylate ligands and being directed over the weaker Sn―N bonds. The in vitro antimicrobial activities of 1–4 against a Gram‐positive bacteria strain (Bacillus subtilis), a Gram‐negative bacteria strain (Escherichia coli) and against Candida albicans were studied and compared with the antimicrobial activities of Ph2SnL2 and Me2SnL2, and with the antimicrobial standards gentamicin, tetracycline, ampicillin and penicillin. All organotin compounds displayed remarkable antibacterial activities that were comparable to those of the standard drugs, in particular against B. subtilis, where the activity was correlated with the number of Cl substituents. Copyright © 2012 John Wiley &amp; Sons, Ltd.

Syntheses and structural characterization of organotin(IV) complexes derived from reaction of 2,3-diphenylpropionic acid and various alkyltin salts

Five new organotin(IV) complexes, [(R3Sn)(O2C15H13)] n (R = Me: 1; nBu: 2), [RSn(O)(O2C15H13)]6 (R = Ph: 3), [(R2Sn)2(O2C15H13)2(μ 3-O)]2 (R = Me: 4), and [(R2Sn)(O2C15H13)2] (R = nBu: 5), have been prepared by the reaction of 2,3-diphenylpropionic acid and the corresponding organotin chloride with sodium ethoxide in methanol. All the complexes were characterized by elemental analysis, FT-IR, NMR (1H, 13C, 119Sn) spectroscopy, TGA, and X-ray crystallography. The structural analyses reveal that 1 and 2 are 1-D infinite polymeric chains with Sn in syn–anti conformation. Complex 3 has a drum structure with six Sn centers. Complex 4 has a supramolecular chain-like ladder through weak intermolecular Sn ··· O interactions. Complex 5 is a monomer, connected into a 1-D polymer through intermolecular C–H ··· O interactions. Complexes 1 and 5 crystallize in the orthorhombic space groups P212121 and P21212, which are chiral space groups.

Dibromodiphenylstannane: isolated centrosymmetric dimers as a new structure motif for the intermolecular association of diorganotin(IV) dihalides

In the crystalline state, the low-melting title compound [common name: diphenyltin(IV) dibromide], [SnBr(2)(C(6)H(5))(2)], consists of distorted tetrahedral molecules with compressed halide and enlarged carbon opening angles of 102.741 (9) and 123.53 (8)°, respectively, and Sn-C and Sn-Br bond lengths of 2.109 (2)/2.113 (2) and 2.4710 (3)/2.4947 (3) Å, respectively. Intermolecular Sn...Br interactions, typical for diorganotin(IV) dihalides, R(2)SnHal(2) (with Hal = Cl, Br, I), and sterically less demanding organic groups lead to the formation of a hitherto unknown association pattern consisting of centrosymmetric dimers with an antiparallel orientation of the dipole moments and two weak intermolecular Sn...Br distances of 3.8482 (3) Å between one of the two Br atoms and its neighbouring Sn atom, and vice versa. The second Br atom is not involved in intermolecular interactions and lies somewhat outside the association plane that, therefore, is not coplanar [interplanar angle = 1.750 (2)°] with the tin-halide plane. The new structure motif of intermolecular tin-halide interaction can be classified as 2a(i), which indicates the number of molecules (i.e. '2') composing the oligomer, the antiparallel orientation (i.e. 'a') of their dipole moments and the centre of symmetry (i.e. 'i') giving rise to the association pattern.