Gold(I) Complexation with Trialkyl/Triaryl Phosphine Selenide Ligands

Abstract

A number of phosphine selenide ligands and their gold(I) complexes of general formula R₃P?Se?Au?X (where X is Cl^?, Br^? and CN^? and R = phenyl, cyclohexyl and tolyl) were prepared. The complexes were characterized by elemental analysis, IR and ³¹P NMR spectroscopic methods. In the IR spectra of all complexes a decrease in frequency of P?Se bond upon coordination was observed, indicating a decrease in P?Se bond order. ³¹P NMR showed that the electronegativity of the substituents is the most important factor determining the ³¹P NMR chemical shift. It was observed that phosphorus resonance is more downfield in alkyl substituted phosphine selenides, as compared to the aryl substituted ones. Ligand disproportionation in the complex Cy₃P?SeAuCN in solution to form [Au(CN)₂]^? and [(Cy₃P?Se)₂Au]⁺ was investigated by ¹³C and ¹⁵N NMR spectroscopy.     

Oxidative addition reactions of [Pt(CN)4]2−; A 13C and 195Pt NMR study

¹³C and ¹⁹⁵Pt NMR measurements show that complexes of the type trans-[Pt(CN)₄X₂]^2? are formed on addition of X₂ (X = Br, Cl, I) to M₂[Pt(CN)₄] (M = K or NBu₄) in aqueous and chloroform solution respectively. Addition of ICN to K₂[Pt(CN)₄] (60% ¹³CN^?) in aqueous solution results in the formation of potassium pentacyanoiodoplatinate(IV) with complete¹³CN^?/¹²CN^?scrambling. The reaction of equi-molar amounts of trans-[PtX₂(CN)₄]^2? (X = Br and Cl), which was previously claimed to result in complete transformation into trans-[PtBrCl(CN)₄]^2?, is instead shown to result in an approximately statistical redistribution of halogens. A progressive shift of δ_Pt to high field is observed on successive replacement of ¹²CN^? by ¹³CN^? in [Pt(CN)₄]^2?.     

Salts of HCN‐Cyanide Aggregates: [CN(HCN)2]− and [CN(HCN)3]−

Although pure hydrogen cyanide can spontaneously polymerize or even explode, when initiated by small amounts of bases (e.g. CN^?), the reaction of liquid HCN with [WCC]CN (WCC=weakly coordinating cation=Ph₄P, Ph₃PNPPh₃=PNP) was investigated. Depending on the cation, it was possible to extract salts containing the formal dihydrogen tricyanide [CN(HCN)₂]^? and trihydrogen tetracyanide ions [CN(HCN)₃]^? from liquid HCN when a fast crystallization was carried out at low temperatures. X‐ray structure elucidation revealed hydrogen‐bridged linear [CN(HCN)₂]^? and Y‐shaped [CN(HCN)₃]^? molecular ions in the crystal. Both anions can be considered members of highly labile cyanide‐HCN solvates of the type [CN(HCN)_n]^? (n=1, 2, 3 …) as well as formal polypseudohalide ions.     

Charakterisierung von Distorsionsisomeren der Anionen Pentacyano-oxo-molybdat(IV) sowie Tetracyano-oxo-aqua-molybdat(IV) im festen Zustand. Kristallstrukturen von [(C6H5)4P]3[MoO(CN)5] · 7 H2O(grün), [(C6H5)4As]2 [MoO(OH2)(CN)4] · 4 H2O (blau) und [(C6H5)4P]2[MoO(OH2)(CN)4] · 4 H2O (grün)

Characterization of Distortional Isomers of the Anions Pentacyano-oxo-molybdate(IV) and of Tetracyano-aqua-oxo-molybdate(IV) in the Solid State. Crystal Structures of [(C₆H₅)₄P]₃[MoO(CN)₅] · 7 H₂O (green), [(C₆H₅)₄As]₂[MoO(OH₂)(CN)₄] · 4 H₂O (blue), and [(C₆H₅)₄P]₂[MoO(OH₂) (CN)₄] · 4 H₂O (green) Preparation of a series of salts containing the new pentacyano-oxo-molybdate(IV) anion is described: Cs₂H[MoO(CN)₅] (blue), [(CH₃)₄N]₂H[MoO(CN)₅] · 2 H₂O (blue) and [Cr(en)₃] [MoO(CN)₅] · 4 H₂O (green). The green [(C₆H₅)₄P]₃[MoO(CN)₅] · 7 H₂O crystallizes triclinic in the space group P1 . The molybdenum(IV) center is in an pseudo-octahedral environment of a terminal oxo-group (d(Mo?O); 1.705(4) Å), a CN^? group in the trans-position (d(Mo? C): 2.373(6) Å), and four equatorial CN^? groups (averaged d(Mo? C): 2.178 (Å). The blue and green salts exhibit v(Mo?O) stretching frequencies at 948 cm^?1 and 920 cm^?1, respectively. Blue and green salts containing the [MoO(OH₂)(CN)₄]^2? anion and [(C₆H₅)₄P]⁺ or [(C₆H₅)₄As]⁺ cations have been prepared and characterized by single crystal crystallography. [(C₆H₅)₄P]₂[MoO(OH₂)(CN)₄] · 4 H₂O (green) and [(C₆H₅)₄As]₂[MoO(OH₂)(CN)₄] · 4 H₂O (blue) crystallize monoclinic in the space group C—P2₁/n. They are considered to be distortional isomers of the complex anion: the green species has a Mo?O bond distance of 1.72(2) Å whereas for the blue species d(Mo?O) = 1.60(2) Å is found; the corresponding v(Mo?O) frequencies are at 920 cm^?1 and 980 cm^?1.     

NMR and kinetic studies of the interactions of [Au(cis-DACH)Cl2]Cl and [Au(cis-DACH)2]Cl3 with potassium cyanide in aqueous solution

The interactions of [Au(cis-DACH)Cl₂]Cl and [Au(cis-DACH)₂]Cl₃ [where cis-DACH is cis-1,2-diaminocyclohexane] with enriched KCN were carried out in CD₃OD and D₂O, respectively. The reaction pathways of these complexes were studied by ¹H, ¹³C, ¹⁵N NMR, UV spectrophotometry, and electrochemistry. The kinetic data for the reaction of cyanide with [Au(cis-DACH)₂]Cl₃ are k = 18 M^?1s^?1, ?H^≠ = 11 kJ M^?1, ?S^≠ = ?185 JK^?1 M^?1, and E_a = 13 kJ M^?1 with square wave voltammetric (SWV) peak +1.35 V, whereas the kinetic data for the reaction of cyanide ion with [Au(cis-DACH)Cl₂]Cl are k = 148 M^?1s^?1, ?H^≠ = 39 kJM^?1, ?S^≠ = ?80 JK^-1 M^?1, and E_a = 42 kJM^?1 along with SWV peak +0.82 V, indicating much higher reactivity of [Au(cis-DACH)Cl₂]Cl toward cyanide than [Au(cis-DACH)₂]Cl₃. The interaction of these complexes with potassium cyanide resulted in an unstable [Au(¹³CN)₄]^? species which readily underwent reductive elimination reaction to generate [Au(¹³CN)₂]^? and cyanogen.     

Characterising lone-pair activity of lead(II) by 207Pb solid-state NMR spectroscopy: coordination polymers of [N(CN)2]- and [Au(CN)2]- with terpyridine ancillary ligands

A series of lead(II) coordination polymers containing [N(CN)₂]^? (DCA) or [Au(CN)₂]^? bridging ligands and substituted terpyridine (terpy) ancillary ligands ([Pb(DCA)₂] ( 1 ), [Pb(terpy)(DCA)₂] ( 2 ), [Pb(terpy){Au(CN)₂}₂] ( 3 ), [Pb(4′‐chloro‐terpy){Au(CN)₂}₂] ( 4 ) and [Pb(4′‐bromo‐terpy)(μ‐OH₂)_0.5{Au(CN)₂}₂] ( 5 )) was spectroscopically examined by solid‐state ²⁰⁷Pb MAS NMR spectroscopy in order to characterise the structural and electronic changes associated with lead(II) lone‐pair activity. Two new compounds, 2 and [Pb(4′‐hydroxy‐terpy){Au(CN)₂}₂] ( 6 ), were prepared and structurally characterised. The series displays contrasting coordination environments, bridging ligands with differing basicities and structural and electronic effects that occur with various substitutions on the terpyridine ligand (for the [Au(CN)₂]^? polymers). ²⁰⁷Pb NMR spectra show an increase in both isotropic chemical shift and span (Ω) with increasing ligand basicity (from δ_iso=?3090 ppm and Ω=389 ppm for 1 (the least basic) to δ_iso=?1553 ppm and Ω=2238 ppm for 3 (the most basic)). The trends observed in ²⁰⁷Pb NMR data correlate with the coordination sphere anisotropy through comparison and quantification of the Pb? N bond lengths about the lead centre. Density functional theory calculations confirm that the more basic ligands result in greater p‐orbital character and show a strong correlation to the ²⁰⁷Pb NMR chemical shift parameters. Preliminary trends suggest that ²⁰⁷Pb NMR chemical shift anisotropy relates to the measured birefringence, given the established correlations with structure and lone‐pair activity.     

Pseudo Halide Chemistry in Ionic Liquids with Decomposable Anions

Several pseudohalide containing ionic liquids with quarternary ammonium counter cations of the general formula [R₃MeN]X [R = ethyl ( 1X ), n‐butyl ( 2X ) with X^– = CN^–, N₃^–, OCN^–, and SCN^–] were synthesized by decomposition of the corresponding trialkylammonium methylcarbonate in the reaction with Me₃Si–X. We also treated 2CN with OP(OMe)₃, yielding [nBu₃MeN][O₂P(OMe)₂] and acetonitrile (Me‐CN). The double salt [nBu₃MeN]₂{[B(OMe)₃(CN)](CN)} was obtained from the reaction of 2CN with B(OMe)₃, featuring the formation of the monocyanotrimethoxyborate anion, [B(OMe)₃(CN)]^–, co‐crystallized with [nBu₃MeN]CN. [nBu₃MeN]₂{[B(OMe)₃(CN)](CN)} was fully characterized including structure elucidation.     

Study of mechanistic features of tetrahedral-octahedral interconversion of tetracyanozincate (II) to bis(4-(2hyphen;Pyridylazo)hyphen;resorcinol)zincate(II) by stopped-flow technique

The present study examines the kinetics and mechanism of the formation of [Zn(CN)₄]^2? from ZnR₂^2? (R represents 4-(2-Pyridylazo)resorcinol, short named as Par) and vice versa. The reactions have been followed at 494 nm (λ_max of [Zn(Par)₂]^2?, ε = 7.8 × 10⁴ M^?1 cm^?1) using stopped-flow spectrophotometer in presence of excess of incoming ligand. The data show that the formation of [Zn(CN)₄]^2? complex is first order in [ZnR₂^2?] and the order with respect to [CN^?] varies from one at higher cyanide concentration to zero at low [CN^?]. These observations suggest a slow dissociation of [ZnR₂]^2? to ZnR and R^2? and a cyanide assisted rapid dissociation of [ZnR₂]^2? to [ZnR(CN)_x]^x? followed by their rapid conversion to [Zn(CN)₄]^2?. The reaction of Zn(Par) with cyanide ions also follow first order kinetics at higher as well as lower cyanide concentrations. The reverse reaction exhibits first order dependence each in [Zn(CN)₄^2?] and [Par^2?], but an inverse first order dependence in [CN^?] at low Par concentrations. However, at higher Par concentration the reaction rate tends to be independent of [Par^2?]. On the basis of forward and reverse rate studies, a five step mechanism consistent with these results has been proposed. The activation parameters and the effect of ionic strength have been used in further support to the proposed mechanism. The effect of pH on the rates of forward and reverse reaction has also been investigated.     

Crystal Structure and Structural Transformation of [(CH3)3NH]2[CuZn(CN)5]

A newly synthesized coordination polymer, [(CH₃)₃NH]₂[CuZn(CN)₅], was investigated using ¹³C and ⁶³Cu solid‐state NMR techniques and single‐crystal X‐ray diffractometry. It consists of a three‐dimensional (3D) net composed of tetrahedral Cu^I and Zn^II ions and CN^– ligands bridging between the two metal ions. (CH₃)₃NH⁺ ions are trapped in the inner space of the 3D net. Three coordination sites of each metal ion are used for the formation of the 3D net and the remaining site is occupied by a unidentate CN^– ligand. The structure of the 3D net is chiral and categorized as srs in the notation of the Reticular Chemistry Structure Resource (RCSR). In water vapor or open air at room temperature under ambient pressure, a powder of [(CH₃)₃NH]₂[CuZn(CN)₅] showed a structural transformation to [(CH₃)₃NH][CuZn(CN)₄] · 1.5H₂O, which is a known compound with a diamond‐like 3D net of [CuZn(CN)₄]^– composed of tetrahedral Cu^I and Zn^II ions and bridging CN^– ligands. ⁶³Cu solid‐state NMR spectroscopy revealed that the Cu‐CN‐Zn orientation of the bridging CN^– ligands was conserved after the structural transformation.     

SYNTHESES AND STRUCTURES OF CLUSTER COMPOUNDS CONTAINING WSe4Cun (n = 3,4) CORES WITH DIALKYLDITHIOCARBAMATE LIGANDS

Abstract

The reactions of [Et₄N]₂[WSe₄] with three equivalents of CuCl in the presence of NaS₂CNR₂ (R = Me, Et) yielded two W-Cu-Se compounds, [Et₄N]₂[WCu₃Se₄(Et₂NCS₂)₃] (1) and [Et₄N]₂-[WCu₄Se₄(Me₂NCS₂)₄] (2). [Et₄N]₂[MoCu₃Se₄(Et₂NCS₂)₃] (1) crystallizes in the orthorhombic space group P2₁2₁2₁ with cell dimensions a = 12.976(3), b = 13.336(3) and c = 29.738(6)Å, V = 5153.8(13)ų, Z = 4. Full anisotropic refinement of the structure led to convergence at R = 0.061 (R_w = 0.070) for 453 variables and 5913 reflections with F>4.0σ(F). The [WCu₃-Se₄(Et₂NCS₂)₃]^2- anion in 1 comprises three Et₂NCS₂Cu fragments linked by a slightly distorted tetrahedral WSe₄ moiety. Compound 2 crystallizes in the orthorhombic space group Pbca with cell constants a = 14.698(3), b = 18.473(4), c = 37.182(5)Å, V = 10095.6(33) ų and Z = 8. Anisotropic refinement with 5839 reflections (F > 6.0σ(F)) and 460 parameters for all non-hydrogen atoms yielded the values R = 0.061 and R_w = 0.073. The [WCu₄Se₄(Me₂NCS₂)₄]^2- anion structure of 2 possesses pseudo D_2d symmetry for the WSe₄Cu₄ core and a nearly planar WCu₄ array and consists of four Me₂NCS₂Cu fragments coordinated across four edges of the tetrahedral [WSe₄]^2- group. IR and electronic spectroscopic data for the two compounds are reported.     

Chalkogenohalogenogallate(III) und -indate(III): Eine neue Verbindungsklasse in der dritten Hauptgruppe. Synthese und Struktur von [Ph4P]2[In2SX6], [Et4N]3[In3E3Cl6] · MeCN und [Et4N]3[Ga3S3Cl6] · THF (X = Cl,Br; E = S,Se)

Chalcogenohalogenogallates(III) and -indates(III): A New Class of Compounds for Elements of the Third Main Group. Preparation and Structure of [Ph₄P]₂[In₂SX₆], [Et₄N]₃[In₃E₃Cl₆] · MeCN and [Et₄N]₃[Ga₃S₃Cl₆] · THF (X = Cl, Br; E = S, Se) [In₂SCl₆]^2?, [In₂SBr₆]^2?, [In₃S₃Cl₆]^3?, [In₃Se₃Cl₆]^3?, and [Ga₃S₃Cl₆]^3? were synthesised as the first known chalcogenohalogeno anions of main group 3 elements. [Ph₄P]₂[In₂SCl₆] ( 1 ) (P1 ; a = 10.876(4) Å, b = 12.711(6) Å, c = 19.634(7) Å, α = 107.21(3)°, β = 96.80(3)°, γ = 109.78(3)°; Z = 2) and [Ph₄P]₂[In₂SBr₆] ( 2 ) (C2/c; a = 48.290(9) Å, b = 11.974(4) Å, c = 17.188(5) Å, β = 93.57(3)°, Z = 8) were prepared by reaction of InX₃, (CH₃)₃SiSSi(CH₃)₃ and Ph₄PX (X = Cl, Br) in acetonitrile. The reaction of MCl₃ (M = Ga, In) with Et₄NSH/Et₄NSeH in acetonitrile gave [Et₄N]₃[In₃S₃Cl₆] · MeCN ( 3 ) (P2₁/c; a = 17.328(4) Å, b = 12.694(3) Å, c = 21.409(4) Å, β = 112.18(1)°, Z = 4), [Et₄N]₃[In₃Se₃Cl₆] · MeCN ( 4 ) (P2₁/c; a = 17.460(4) Å, b = 12.816(2) Å, c = 21.513(4) Å, β = 112.16(2)°, Z = 4), and [Et₄N]₃[Ga₃S₃Cl₆] · THF ( 5 ) (P2₁/n; a = 11.967(3) Å, b = 23.404(9) Å, c = 16.260(3) Å, β = 90.75(2)°, Z = 4). The [In₂SX₆]^2? anions (X = Cl, Br) in 1 and 2 consist of two InSX₃ tetrahedra sharing a common sulfur atom. The frameworks of 3, 4 and 5 each contain a six-membered ring of alternating metal and chalcogen atoms. Two terminal chlorine atoms complete a distorted tetrahedral coordination sphere around each metal atom.     

Reductive nitrosylation of tetraoxometallates. part V1. single pot and A virtually single step synthesis of chromium(l) cyanonitrosyl derivatives directly from chromate(VI) in aqueous-aerobic media.

Cyanonitrosyl complexes and their derivatives of the types [Cr(NO)(CN)₄]^2?, [Cr(NO)(CN)₃H₂O]^? and [Cr(NO)(CN)₂ LL] [LL = 2,2′ bipyridine (bipy) or 1, 10-Phenanthroline (phen)] are synthesised directly from CrO₄^2? using NH₂OH.HCl, OH^? and CN^? and other appropriate ligands, virtually in a single step process in an aqueous aerobic medium. The compounds are characterised by IR, molar conductance, magnetic susceptibility, e.s.r, electronic spectra and thermoanalytical data.     

Structural study of C,N‐chelated monoorganotin(IV) halides

Three monoorganotin(IV) compounds of general formula L^CNSnX₃, where L^CN is a 2‐(dimethylaminomethyl)phenyl‐ group and X = Cl ( 1 ), Br ( 2 ) and I ( 3 ), were prepared and characterized using XRD and NMR techniques. Compound 1 reacts with moisture producing [(L^CN)₂HSnCl₂]⁺ [L^CNSnCl₄]^?. Compound 3 decomposes to (L^CN)₂SnI₂, SnI₂ and I₂ when heated. Compound 2 was reacted with NH₄F yielding an equilibrium of fluorine‐containing species. The major products were [L^CNSnF₅]^2? and [(L^CNSnF₃)₂(µ²‐F)₂]^2? (4a). When compound 2 was reacted with another fluorinating agent, L^CN(n‐Bu)₂SnF, an oligomeric product, [L^CNSnF₂(µ²‐F)₂]_n, was observed. Further addition of NH₄F led to subsequent formation of 4a. The structure of fluorinated products was investigated by ¹H, ¹⁹F and ¹¹⁹Sn NMR spectroscopy. Copyright © 2006 John Wiley & Sons, Ltd.     

Reduction of Digallane [(dpp‐bian)Ga?Ga(dpp‐bian)] with Group 1 and 2 Metals

The reduction of digallane [(dpp‐bian)Ga? Ga(dpp‐bian)] ( 1 ) (dpp‐bian=1,2‐bis[(2,6‐diisopropylphenyl)imino]acenaphthene) with lithium and sodium in diethyl ether, or with potassium in THF affords compounds featuring the direct alkali metal–gallium bonds, [(dpp‐bian)Ga? Li(Et₂O)₃] ( 2 ), [(dpp‐bian)Ga? Na(Et₂O)₃] ( 3 ), and [(dpp‐bian)Ga? K(thf)₅] ( 7 ), respectively. Crystallization of 3 from DME produces compound [(dpp‐bian)Ga? Na(dme)₂] ( 4 ). Dissolution of 3 in THF and subsequent crystallization from diethyl ether gives [(dpp‐bian)Ga? Na(thf)₃(Et₂O)] ( 5 ). Ionic [(dpp‐bian)Ga]^?[Na([18]crown‐6)(thf)₂]⁺ ( 6 a ) and [(dpp‐bian)Ga]^?[Na(Ph₃PO)₃(thf)]⁺ ( 6 b ) were obtained from THF after treatment of 3 with [18]crown‐6 and Ph₃PO, respectively. The reduction of 1 with Group 2 metals in THF affords [(dpp‐bian)Ga]₂M(thf)_n (M=Mg ( 8 ), n=3; M=Ca ( 9 ), Sr ( 10 ), n=4; M=Ba ( 11 ), n=5). The molecular structures of 4 – 7 and 11 have been determined by X‐ray crystallography. The Ga? Na bond lengths in 3 – 5 vary notably depending on the coordination environment of the sodium atom.     

Solution and solid state NMR studies of some selenium analogues of auranofin (an anti-arthritic gold drug)

Three mixed ligand complexes of gold(I) with phosphines and selenones, [Et₃PAuSe=C<]Br as analogues of auranofin (Et₃PAuSR) have been prepared and characterized by elemental analysis, IR and NMR methods. A decrease in the IR frequency of the C=Se mode of selenones upon complexation is indicative of selenone binding to gold(I) via a selenone group. An upfield shift in ¹³C NMR for the C=Se resonance of the selenones and downfield shifts in ³¹P NMR for the R₃P moiety are consistent with the selenium coordination to gold(I). ¹³C solid state NMR shows the chemical shift difference between free and bound selenone to gold(I) for ImSe and DiazSe to be ca 10 and 17?ppm respectively. Large ⁷⁷Se NMR chemical shifts (55?ppm) upon complexation in the solid state for [Et₃PAuDiazSe]Br compared to [Et₃PAuImSe]Br (10?ppm) indicates the former to be more stable and the Au–Se bond to be stronger than in the latter complex.     

Activation of CS2 and CO2 by Silylium Cations

The hydride-bridged silylium cation [Et₃Si−H−SiEt₃]⁺, stabilized by the weakly coordinating [Me₃NB₁₂Cl₁₁]⁻ anion, undergoes, in the presence of excess silane, a series of unexpected consecutive reactions with the valence-isoelectronic molecules CS₂ and CO₂. The final products of the reaction with CS₂ are methane and the previously unknown [(Et₃Si)₃S]⁺ cation. To gain insight into the entire reaction cascade, numerous experiments with varying conditions were performed, intermediate products were intercepted, and their structures were determined by X-ray crystallography. Besides the [(Et₃Si)₃S]⁺ cation as the final product, crystal structures of [(Et₃Si)₂SMe]⁺, [Et₃SiS(H)Me]⁺, and [Et₃SiOC(H)OSiEt₃]⁺ were obtained. Experimental results combined with supporting quantum-chemical calculations in the gas phase and solution allow a detailed understanding of the reaction cascade.     

Lewis Acid Catalyzed Synthesis of Cyanidophosphates

Salts containing new cyanido(fluorido)phosphate anions of the general formula [PF_6?n(CN)_n]^? (n=1–4) were synthesized by a very mild Lewis‐acid‐catalyzed synthetic protocol and fully characterized. All [PF_6?n(CN)_n]^? (n=1–4) salts could be isolated on a preparative scale. It was also possible to detect the [PF(CN)₅]^? but not the [P(CN)₆]^? anion. The best results with respect to purity, yield, and low cost were obtained when the F^?/CN^? substitution reactions were carried out in ionic liquids.     

Isoelectronic Aluminium Analogues of Carbonyl and Dioxirane Moieties

We report the anion [Al(NON^Ar)(Se)]^? (NON^Ar=[O(SiMe₂NAr)₂]^2?, Ar=2,6‐iPr₂C₆H₃), which is an isoelectronic Group 13 metal analogue of the carbonyl group containing an aluminium–selenium multiple bond. It was synthesized in a single step from the reaction of the aluminyl anion [Al(NON^Ar)]^? with elemental selenium. Spectroscopic, crystallographic, and computational analysis confirmed multiple bonding between aluminium and selenium. Addition of a second equivalent of selenium afforded the diselenirane, [Al(NON^Ar)(κ²‐Se₂)]^?, which is an isoelectronic analogue of the dioxirane group.     

Synthesis of sulphonated aminomethylphosphines and some nickel(II), palladium(II), platinum(II) and rhodium(I) complexes. Crystal structure of [Et3NH][(Ph2PCH2)2 N(CH2)2SO3]

Summary Aminoalkanesulphonic acids H₂N(CH₂) _n SO₃H, (n = 1, 2 or 3) react with phosphonium salts [R₂P(CH₂OH)₂]Cl (R = Ph or Cy, Cy = cyclohexyl) in the presence of Et₃N to give the sulphonated aminomethylphosphines [Et₃NH] [(R₂PCH₂)₂N(CH₂) _n SO₃] (R = Ph, n = 1, 2 or 3; R = Cy, n = 1). The single crystal X-ray structure of [Et₃NH] [(Ph₂PCH₂)₂N(CH₂)₂SO₃] has been determined. Some Ni^II, Pd^II, Pt^II and Rh^I complexes of the phosphines have been prepared.     

Homoleptic Gold Acetonitrile Complexes with Medium to Very Weakly Coordinating Counterions: Effect on Aurophilicity?

A series of gold acetonitrile complexes [Au(NCMe)₂]⁺[WCA]^? with weakly coordinating counterions (WCAs) was synthesized by the reaction of elemental gold and nitrosyl salts [NO]⁺[WCA]^? in acetonitrile ([WCA]^? = [GaCl₄]^?, [B(CF₃)₄]^?, [Al(OR^F)₄]^?; R^F = C(CF₃)₃). In the crystal structures, the [Au(NCMe)₂]⁺ units appeared as monomers, dimers, or chains. A clear correlation between the aurophilicity and the coordinating ability of counterions was observed, with more strongly coordinating WCAs leading to stronger aurophilic contacts (distances, C?N stretching frequencies of [Au(NCMe)₂]⁺ units). An attempt to prepare [Au(L)₂]⁺ units, even with less weakly basic solvents like CH₂Cl₂, led to decomposition of the [Al(OR^F)₄]^? anion and formation of [NO(CH₂Cl₂)₂]⁺[F(Al(OR^F)₃)₂]^?. All nitrosyl reagents [NO]⁺[WCA]^? were generated according to an optimized procedure and were thoroughly characterized by Raman and NMR spectroscopy. Moreover, the to date unknown species [NO]⁺[B(CF₃)₃CN]^? was prepared. Its reaction with gold unexpectedly produced [Au(NCMe)₂]⁺[Au(NCB(CF₃)₃)₂]^?, in which the cyanoborate counterion acts as an anionic ligand itself. Interestingly, the auroborate anion [Au(NCB(CF₃)₃)₂]^? behaves as a weakly coordinating counterion, which becomes evident from the crystallographic data and the vibrational spectral characteristics of the [Au(NCMe)₂]⁺ cation in this complex. Ligand exchange in the only room temperature stable salt of this series, [Au(NCMe)₂]⁺[Al(OR^F)₄]^?, is facile and, for example, [Au(PPh₃)(NCMe)]⁺[Al(OR^F)₄]^? can be selectively generated. This reactivity opens the possibility to generate various [AuL¹L²]⁺[Al(OR^F)₄]^? salts through consecutive ligand‐exchange reactions that offer access to a huge variety of Au^I complexes for gold catalysis.