First correlation of nanoparticle size-dependent formation with the ionic liquid anion molecular volume

Stable silver nanoparticles are obtained reproducibly by hydrogen reduction of different inorganic precursors from AgIX salts (X = BF4, PF6, OTf) dissolved in the ionic liquids BMim+BF4-, BMim+PF6-, BMim+OTf-, or BtMA+NTf2- [BMim+ = n-butylmethylimidazolium, BtMA+ = n-butyltrimethylammonium, NTf2 = N(O2SCF3)2, and OTf = O3SCF3] in the presence of n-butylimidazole (Bim) as the scavenger for the HX acid byproduct and with a narrow size distribution in the diameter range of 2.8-26.1 nm, which increases linearly with the molecular volume of the ionic liquid anion (transmission electron microscopy characterization).     

Silver complexes of cyclic hexachlorotriphosphazene

The first solid-state structures of complexed P3N3X6 (X = halogen) are reported for X = Cl. The compounds were obtained from P3N3Cl6 and Ag[Al(OR)4] salts in CH2Cl2/CS2 solution. The very weakly coordinating anion with R = C(CF3)3 led to the salt Ag(P3N3Cl6)2+[Al(OR)4]- (1), but the more strongly coordinating anion with R' = C(CH3)(CF3)2 gave the molecular adduct (P3N3Cl6)AgAl(OR')4 (3). Crystals of [Ag(CH2Cl2)(P3N3Cl6)2]+[Al(OR)4]- (2), in which Ag+ is coordinated by two phosphazene and one CH2Cl2 ligands, were isolated from CH2Cl2 solution. The three compounds were characterized by their X-ray structures, and 1 and 3 also by NMR and vibrational spectroscopy. Solution and solid-state 31P NMR investigations in combination with quantum chemically calculated chemical shifts show that the 31P NMR shifts of free and silver-coordinated P3N3Cl6 differ by less than 3 ppm and indicate a very weakly bound P3N3Cl6 ligand in 1. The experimental silver ion affinity (SIA) of the phosphazene ligand was derived from the solid-state structure of 3. The SIA shows that (PNCl2)3 is only a slightly stronger Lewis base than P4 and CH2Cl2, while other ligands such as S8, P4S3, toluene, and 1,2-Cl2C2H4 are far stronger ligands towards the silver cation. The energetics of the complexes were assessed with inclusion of entropic, thermal, and solvation contributions (MP2/TZVPP, COSMO). The formation of the cations in 1, 2, and 3 was calculated to be exergonic by delta(r)G(degrees)(CH2Cl2) = -97, -107, and -27 kJ mol(-1), respectively. All prepared complexes are thermally stable; formation of P3N3Cl5+ and AgCl was not observed, even at 60 degrees C in an ultrasonic bath. Therefore, the formation of P3N3Cl5+ was investigated by quantum chemical calculations. Other possible reaction pathways that could lead to the successful preparation of P3N3X5+ salts were defined.     

Complexation Behavior of Phosphate and Phosphazene Derivatives Containing Three or Six Benzo-15-crown-5 Cavities

Tris(benzocrown ether)s 2a , b X = P(NMeN=CH-B15C5) 3 (X=O, S) and tri[bis(benzocrown ether)] [N=P(NMeN=CH-B15C5) 2 ] 3 3 strongly chelate with alkali metal salts and their efficiency and selectivity in binding these salts are compared with those of the monomeric crown 1 . Data obtained from salt distribution equilibrium in water-chloroform show these ligands to be excellent extracting agents, especially for K + and Rb + . Furthermore, compound 3 is able to transport K + selectively.     

Steric control over the formation of cis and trans bis-chelated palladium(II) complexes using a new series of flexible N,P pyridyl-phosphine ligands

The deprotection of phosphonium chloride salts [PR2(CH2OH)2]+Cl- and subsequent condensation reaction with N-methyl-2-aminopyridine has been carried out to give a series of ligands of the form PR2CH2N(CH3)C5H4N (R=Ph , Cy , t-Bu ) which have been fully characterised either as the pure ligand () or the air stable borane adducts (R=Cy , t-Bu ). The 1:1 reactions of , and with PdCl2(COD) gave the N,P chelate complexes [Pd{PR2CH2N(CH3)C5H4N}Cl2]; the Cy () and t-Bu () complexes were characterised by X-ray crystallography. The bisligated species [Pd{PCy2CH2N(CH3)C5H4N}2Cl2] () was obtained when the reaction was carried out at higher temperatures and the ligands were found to be coordinated to the metal in a trans configuration through the phosphorus donors. Abstraction of the chlorides from the bis-ligated species , using silver salts, resulted in the coordination of the pyridine ring forming the bis-chelate complex [Pd{PCy2CH2N(CH3)C5H4N}2]2+. In comparison, the palladium bis-chelate complex of ligand [Pd{PPh2CH2N(CH3)C5H4N}2]2+ () was shown to form in a cis configuration and was fully characterised by X-ray crystallography.     

Energetic Silver Salts with 5-Aminotetrazole Ligands

Methylation of 5-amino-1H-tetrazole ( 1 ) gives 1-methyl-5-amino-1H-tetrazole ( 2 ) and 2-methyl-5-amino-1H-tetrazole ( 3 ). A new family of energetic silver complexes based on ligands 1 , 2 and 3 with perchlorate and nitrate anions ( 10 – 15 ) were synthesized and characterized by using IR, Raman, and NMR (¹H, ¹³C, ¹⁴N, and ³⁵Cl NMR) spectroscopy, elemental analysis, and mass spectrometry. The crystal structures of the compounds were determined where possible and reveal interesting structural details that are discussed herein. Additionally, differential scanning calorimetry was used to assess the thermal stability of the new salts, which showed excellent thermal stabilities at temperatures up to and above 225 °C. Standard tests were also used to assess the sensitivity of the materials towards impact and friction. All the silver complexes showed increased sensitivity values in comparison with analogous protonated 5-amino-1H-tetrazolium perchlorate and nitrate salts. Some of these materials have sensitivity values that are comparable to commonly used primary explosives and all of them either deflagrate ( 12 – 14 ) or detonate loudly ( 10 and 11 ) on contact with an open flame. Lastly, nitrate salt 11 is easily initiated by thermal shock. It shows reasonably low sensitivity in comparison with other silver salts (e.g., silver azide or silver fulminate), which makes handling it much less hazardous. Compound 11 also has good thermal stability, decomposing at ≈300 °C, and shows interesting properties as a more environmentally benign alternative to lead(II) diazide in initiation devices for civil and military applications.     

Effects of electrolytes on the configuration change of cobalt(II)-halide complexes in chloroform/water reverse micelle systems.

The effects of various salts and HClO4 on the configuration change of cobalt(II)-halide complexes in CHCl3/CTAC or CTAB/H2O reverse micelle systems were examined at 25 degrees C by means of spectrophotometry, where CTAC and CTAB represent cetyltrimethylammonium chloride and bromide, respectively. The formation of the [CoCl4]> or [CoBr4]2- species of the tetrahedral configuration from [Co(H2O)6]2+ of the octahedral configuration in the reverse micelles was greatly promoted not only by a decrease in the W value (W = [H2O]/[surfactant]), but also, at a constant W value (e.g., W = 2.0), by the addition of relatively low concentrations of salts or the acid (e.g., 4.0 mol dm(-3) in the aqueous phase or 4.0 x 10(-2) mol dm(-3) in the whole reverse micelle system). The effects of perchlorate salts increased as Na+ < or = Li+ approximately H+ < Sr2+ < Ca2+ < Mg2+. Non-metallic salts, various tetraalkylammonium (R4N+) salts at lower concentrations, gave minor effects. The enhanced effects of metal salts on the configuration change of the cobalt(II)-halide complexes were interpreted by a further distortion of the hydrogen-bonded structure of the water in a "water pool" in the presence of salts of even relatively low concentrations. A conformation change with increasing temperature was also attributed to a further distortion of the water structure. An almost completed formation of [CoBr4]2- as well as [CoCl4]2- was attained in the reverse micelles at a low W value of 0.69 containing LiClO4 or HClO4. A partial transfer of the [CoX4]2- species from a "water pool" into the CHCl3 phase by the addition of the metal salts may be suspected. An examination of cobalt(II)-bromide complexes in dichloromethane/CTAB/H2O at W = 1.3 - 5.55 justified all the arguments concerning the chloroform systems. The Raman spectra of D2O containing concentrated LiBr and LiClO4 have supplied conclusive evidence that the hydrogen-bonded structure of the bulk water is completely distorted by extremely concentrated salts.     

Alkylation and acylation of cyclotriphosphazenes

Phosphazenes (RNH)6P3N3 (R = n-propyl, isobutyl, isopropyl, cyclohexyl, tert-butyl, benzyl) are readily alkylated at ring N sites by alkyl halides forming N-alkyl phosphazenium cations. Alkylation of two ring N sites occurred after prolonged heating in the presence of methyl iodide or immediately at room temperature with methyl triflate yielding N,N'-dimethyl phosphazenium dications. Geminal dichloro derivatives Cl2(RNH)4P3N3 are methylated by methyl iodide at the ring N site adjacent to both P centers carrying four RNH groups. X-ray crystal structures showed that the alkylation of ring N sites leads to substantial elongation of the associated P-N bonds. Both N-alkyl and N,N'-dialkyl phosphazenium salts form complex supramolecular networks in the solid state via NH...X interactions. Systems carrying less-bulky RNH groups show additional NH...N bonds between N-alkyl phosphazenium ions. N-Alkyl phosphazenium halides form complexes with silver ions upon treatment with silver nitrate. Depending on the steric demand of RNH substituents, either one or both of the vacant ring N sites engage in coordination to silver ions. Treatment of (RNH)6P3N3 (R = isopropyl) with acetyl chloride and benzoyl chloride, respectively, yielded N-acyl phosphazenium ions. X-ray crystal structures revealed that elongation of P-N bonds adjacent to the acylated ring N site is more pronounced than it is in the case of N-alkylated species. Salts containing N-alkyl phosphazenium ions are stable toward water and other mild nucleophiles, while N,N'-dialkyl and N-acyl phosphazenium salts are readily hydrolyzed. The reaction of (RNH)6P3N3 with bromoacetic acid led to N-alkylation at one ring N site in addition to formation of an amide via condensation of an adjacent RNH substituent with the carboxylic acid group. The resulting bromide salt contains mono cations of composition (RNH)5P3N3CH2CONR in which a CH2-C(O) unit is embedded between a ring N and an exocyclic N site of the phosphazene.     

Pentafluorosulfanylnitramide salts

The synthesis and properties of a new class of inorganic salts, named pentafluorosulfanylnitramide salts (or pentafluorosulfanylnitraminic acid salts) [Z+SF5NNO2-], are described. A number of SF5-nitramide salts (Z+SF5NNO2-) were successfully prepared via nucleophilic displacements from carbamates and/or ion exchange techniques, but some salts [M(SF5NNO2)x; M = Li, Mg, Al] decomposed during isolation procedures and appear to be unstable in the solid state. Single-crystal X-ray diffraction was used to fully characterize the Z+SF5NNO2-, and their properties/structures are compared with those of the corresponding dinitramide salts (or dinitraminic acid salts), Z+N(NO2)2-. X-ray crystallography revealed major structural differences between N(NO2)2- and SF5N(NO2)- salts concerning the N-N distances and the angles subtended at the central nitrogen atom. In the N(NO2)2- salts, there are two nonequivalent N-N (average lengths 1.372(2) and 1.354(2) A) distances and an average N-N-N angle of 115.8(3) degrees (falls between sp3 and sp2 hybridization). In the SFsNNO2- salts, the average N-N distance is much shorter, 1.308(9) A, and the average N-N-S angle is 120.0(5) degrees (closely fits sp2 hybridization). The SF5NNO2- salts show a remarkable metrical similarity for the SF5 moiety in all structures, indicating a lack of sensitivity to its steric and electronic environment. This is in marked contrast to N(NO2)2-, where there is a wide variation in conformations adopted by these anions which can be related to their environment.     

Ring-opening polymerisation of coordination compounds: a silver(I) network with both ring and polymer components

The terpyridyl ligand 2,6-C5H3N{C(=O)N(Me)-4-C5H4N}2, 1, combined with silver(I) salts to give the complexes [Ag2(1)2][BF4]2, 2, and [{Ag3(1)2}n][CF3SO3]3n, 3; the network structure of complex contains both macrocyclic units [Ag2(mu-1)2]2+ and ring-opened polymeric units [{Ag(mu-1)}n]n+.     

Assembly of polymeric silver(I) complexes of isomeric phenylenediethynides with the supramolecular synthons Agn subset C2-R-C2 superset Agn (R = p-, m-, o-C6H4; n = 4, 5)

New Agn subset C2-R-C2 supersetAgn (R = p-, m-, o-C6H4; n = 4, 5) supramolecular synthons have been explored in the coordination network assembly of silver(I) complexes of the isomeric phenylenediethynides. An unprecedented mu5-eta1-coordination mode for the ethynide moiety and a mixed mu4,mu5-coordination mode for the o-phenylenediethynide group are observed, providing a rationale for the abundant occurrence of C2@Agn (n 相似文献   

Energetic bicyclic azolium salts

Bicyclic azoles, 2-methyl-5-(imidazol-1-yl)-2H-tetrazole (1), 2-methyl-5-(1,2,4-triazol-1-yl)-2H-tetrazole (4), 1-methyl-5-(imidazol-1-yl)-1H-tetrazole (7), 1-methyl-5-(1,2,4-triazol-1-yl)-1H-tetrazole (10), 1-methyl-4-nitro-2-(imidazol-1-yl)-1H-imidazole (13), and 1-methyl-4-nitro-2-(1,2,4-triazol-1-yl)-1H-imidazole (16) were prepared. Their thermally stable azolium salts, 3, 6, 9, 12, 15, and 18-21, with densities ranging between 1.519-1.674 g cm-3, were synthesized by quaternization with nitric or perchloric acid or with iodomethane followed by metathesis reactions with silver nitrate and silver perchlorate. The structures of 12 b and 21 b were confirmed by single-crystal X-ray analysis. The standard enthalpies of formation for some of the new salts were calculated by using the computationally feasible DFT(B3LYP) and MP2 methods in conjunction with an empirical approach based on densities of salts. The calculated values range from DeltaHdegreef=209.9 (21 a) to 412.3 (12 b) kJ mol-1 in which the experimental densities are >1.515 g cm-3.     

Homochiral and heterochiral coordination polymers and networks of silver(I)

The self-assembly of racemic and enantiopure binaphthylbis(amidopyridyl) ligands 1,1'-C(20)H(12){NHC(O)-4-C(5)H(4)N}(2), 1, and 1,1'-C(20)H(12){NHC(O)-3-C(5)H(4)N}(2), 2, with silver(I) salts (AgX; X = CF(3)CO(2), CF(3)SO(3), NO(3)) to form extended metal-containing arrays is described. It is shown that the self-assembly with racemic ligands can lead to homochiral or heterochiral polymers, through self-recognition or self-discrimination of the ligand units. The primary polymeric materials adopt helical conformations (secondary structure), and they undergo further self-assembly to form sheets or networks (tertiary structure). These secondary and tertiary structures are controlled through secondary bonding interactions between pairs of silver(I) centers, between silver cations and counteranions, or through hydrogen bonding involving amide NH groups. The self-assembly of the enantiopure ligand R-1 with silver trifluoroacetate gave a remarkable three-dimensional chiral, knitted network composed of polymer chains in four different supramolecular isomeric forms.     

Pyridine-2-carboxaldehyde as ligand: synthesis and derivatization of carbonyl complexes

Thermally induced carbonyl substitutions on [M(CO)5X] (M=Mn, X=Cl, Br; M=Re, X=Br) or room temperature displacement of acetonitrile from [Mo(eta3-methallyl)Cl(CO)2(NCMe)2] produce stable crystalline complexes containing pyridine-2-carboxaldehyde (pyca) as chelate kappa2(N,O) ligands (). These react with ethylglycine to afford iminopyridine complexes containing an amino ester pendant arm in high-yield. Treatment with silver salts produce halide abstraction affording neutral complexes containing coordinated perchlorate or triflate which can be replaced by triphenyl phosphine to give cationic complexes . As confirmed by spectroscopy and X-ray crystallography the pyca ligand remains bonded as chelate kappa2(N,O) throughout these processes.     

The OsO4F-, OsO4F2(2)-, and OsO3F3- anions, their study by vibrational and NMR spectroscopy and density functional theory calculations, and the X-ray crystal structures of [N(CH3)4][OsO4F] and [N(CH3)4][OsO3F3

The fluoride ion acceptor properties of OsO4 and OsO3F2 were investigated. The salts [N(CH3)4][OsO4F] and [N(CH3)4]2[OsO4F2] were prepared by the reactions of OsO4 with stoichiometric amounts of [N(CH3)4][F] in CH3CN solvent. The salts [N(CH3)4][OsO3F3] and [NO][OsO3F3] were prepared by the reactions of OsO3F2 with a stoichiometric amount of [N(CH3)4][F] in CH3CN solvent and with excess NOF, respectively. The OsO4F- anion was fully structurally characterized in the solid state by vibrational spectroscopy and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO4F]: Abm2, a = 7.017(1) A, b = 11.401(2) A, c = 10.925(2) A, V = 874.1(3) A3, Z = 4, and R = 0.0282 at -50 degrees C. The cis-OsO4F2(2-) anion was characterized in the solid state by vibrational spectroscopy, and previous claims regarding the cis-OsO4F2(2-) anion are shown to be erroneous. The fac-OsO3F3- anion was fully structurally characterized in CH3CN solution by 19F NMR spectroscopy and in the solid state by vibrational spectroscopy of its N(CH3)4+ and NO+ salts and by a single-crystal X-ray diffraction study of [N(CH3)4][OsO3F3]: C2/c, a = 16.347(4) A, b = 13.475(3) A, c = 11.436(3) A, beta = 134.128(4) degrees, V = 1808.1(7) A3, Z = 8, and R = 0.0614 at -117 degrees C. The geometrical parameters and vibrational frequencies of OsO4F-, cis-OsO4F2(2-), monomeric OsO3F2, and fac-OsO3F3- and the fluoride affinities of OsO4 and monomeric OsO3F2 were calculated using density functional theory methods.     

Stereochemistry of cyclic ether formation—II : Intramolecular cyclisation of secondary aliphatic alcohols to tetrahydrofuran-type ethers

The mechanism and stereochemistry of δ-C atom functionalisation in the reactions of secondary straight-chain aliphatic alcohols with lead tetraacetate, ceric ammonium nitrate, and heavy metal (Pb⁴⁺, Hg²⁺, Ag⁺) salts (AcO)^?1, O^2?, CO₃^2?-halogen (I₂, Br₂, Cl₂) combinations are discussed. By demonstrating the intermediacy of 5-bromo-2-hexanol, it was confirmed that the dark silver oxidebromine induced cyclisation of 2-hexanol (and alcohols in general) involves (as the other hypohalite reactions) intramolecular 1,5-hydrogen abstraction by alkoxy radicals and formation of δ-bromohydrins. A novel and simple procedure for obtaining tetrahydrofurans from alcohols by way of the hypochlorite reaction, using silver or mercuric salts and chlorine, is described.     

Gas phase synthesis and reactivity of Agn+ and Ag(n-1)H+ cluster cations

Multi-stage mass spectrometry (MSn) on [(M + Ag - H)x + Ag]+ precursor ions (where M = an amino acid such as glycine or N,N-dimethylglycine) results in the formation of stable silver (Ag3+, Ag5+ and Ag7+) and silver hydride (Ag2H+, Ag4H+ and Ag6H+) cluster cations in the gas phase. Deuterium labelling studies reveal that the source of the hydride can be either from the alpha carbon or from one of the heteroatoms. When M = glycine, the silver cyanide clusters Ag4CN+ and Ag5(H,C,N)+ are also observed. Collision induced dissociation (CID) and DFT calculations were carried out on each of these clusters to shed some light on their possible structures. CID of the Agn+ and Ag(n-1)H+ clusters generally results in the formation of the same Ag(n-2)+ product ions via the loss of Ag2 and AgH respectively. DFT calculations also reveal that the Agn+ and Ag(n-1)H+ clusters have similar structural features and that the Ag(n-1)H+ clusters are only slightly less stable than their all silver counterparts. In addition, Agn+ and Ag(n-1)H+ clusters react with 2-propanol and 2-butylamine via similar pathways, with multiple ligand addition occurring and a coupled deamination-dehydration reaction occurring upon condensation of a third (for Ag2H+) or a fourth (for all other silver clusters) 2-butylamine molecule onto the clusters. Taken together, these results suggest that the Agn+ and Ag(n-1)H+ clusters are structurally related via the replacement of a silver atom with a hydrogen atom. This replacement does not dramatically alter the cluster stability or its unimolecular or bimolecular chemistry with the 2-propanol and 2-butylamine reagents.     

Stable CI3+ salts and attempts to prepare CHI2+ and CH2I+

The room-temperature stable CI3+ salts [CI3+[pftb](-)1 and [CI3]+[al-f-al](-) 2([pftb](-) = [Al(OC(CF3)3)4](-); [al-f-al](-) = [((CF3)3CO)3Al-F-Al(OC(CF3)3)3](-)) were prepared in quantitative yields from purified CI4 and the corresponding silver aluminates with total exclusion of light (NMR, IR, UV-VIS, X-ray diffraction). The isolated CI(3)(+) cation is trigonal planar with a sum of <(I-C-I) = 360.0 degrees (1) and 359.9 degrees (2). Attempts to prepare CHI2+ and CH2I+ salts from CHI3 or CH2I2/Ag[pftb] mixtures remained unsuccessful; the reaction with CH2I2 leads to the formation of the adduct [Ag(CH2I2)3]+[pftb](-)3, while for HCI3, dismutation with formation of 1 as well as 3 was observed. All particles were also calculated at the MP2/TZVPP level to predict the vibrational and electronic spectra as well as to calculate the Gibbs free energies of all reactions (DeltaG degrees , gas phase and CH2Cl2 solution). Quantum chemical calculations were also used to investigate the stability of the [pftb](-) anion against the electrophilic attack of the CX3+ and CHnX3-n+ cations (X = F-I, n = 1-3). The strength of the Lewis acidity of these cations and of the isoelectronic boron halides BX()and BHnX3-n have been established on the basis of their fluoride ion affinities (FIAs). The FIAs of the carbon and the boron containing compounds show opposite trends, with fluorinated halomethyl cations being stronger acids than their heavier congeners but iodinated holoboranes being stronger acids than their lighter homologues.     

Disilver(I) macrocycles: variation of cavity size with anion binding

Reaction of the N-methylated bis(amidopyridine) ligand, LL = C6H4(1,3-CONMe-4-C5H4N)2, with the silver salts AgNO3, AgO2CCF3, AgO3SCF3, AgBF4, and AgPF6 gave the corresponding cationic disilver(I) macrocycles [Ag2(micro-LL)2]X2, 2a-e. The transannular silver...silver distance in the macrocycles varies greatly from 2.99 to 7.03 A, and these differences arise through a combination of different modes ofanion binding and from the presence or absence of silver...silver secondary bonding. In all complexes, the ligand adopts a conformation in which the methyl group and oxygen atom of the MeNCO units are mutually cis, but the overall macrocycle can exist in either boat (X = PF6 only) or chair conformation. Short transannular silver...silver distances are found in complexes 2b,c, in which the anions CF3CO2- and CF3SO3- bind above and below the macrocycle, but longer silver...silver distances are found for 2a,d,e, in which the anions are present, at least in part, inside the disilver macrocycle. Easy anion exchange occurs in solution, and studies using ESI-MS indicate that the anion binding to form [Ag2X(micro-LL)2]+ follows the sequence X = CF3CO2- > NO3- > CF3SO3-.     

Impact of ionic liquids on silver thermoplastic polyurethane composite membranes for propane/propylene separation

This work describes newly synthesized composite polymeric membranes and their utilization in propane/propylene separation in a gas mixture. The nonporous composite polymers were successfully synthesized by using thermoplastic polyurethane (TPU) and several silver salts/silver salts with ionic liquids (ILs). Our studies showed that silver bis(trifluoromethanesulfonyl)imide (Ag[Tf₂N]) containing membranes outperformed other silver salt containing membranes in terms of selectivity. In addition, to this finding, ILs, as additives for the membranes, enhanced the selectivity by facilitating improved coordination of the olefin with the silver ions in the dense composite polymers.     

Noncyclic [10-S-5] sulfuranide dioxide salts with three S-C bonds: a new class of stable hypervalent compounds

Phenyl triflate reacts with CF3SiMe3/Q+F- (Q+ = [K(18-crown-6)]+, Me4N+) and (Me2N)3S+Me3SiF2- to afford the first noncyclic [10-S-5] sulfuranide dioxide salts, [(CF3)3SO2]-Q+, with three S-C bonds, whose molecular structure was determined by X-ray crystallography.