PC‐Activated Bimetallic Rhodium Xantphos Complexes: Formation and Catalytic Dehydrocoupling of Amine–Boranes

{Rh(xantphos)}‐based phosphido dimers form by P? C activation of xantphos (4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene) in the presence of amine–boranes. These dimers are active dehydrocoupling catalysts, forming polymeric [H₂BNMeH]_n from H₃B?NMeH₂ and dimeric [H₂BNMe₂]₂ from H₃B?NMe₂H at low catalyst loadings (0.1 mol %). Mechanistic investigations support a dimeric active species, suggesting that bimetallic catalysis may be possible in amine–borane dehydropolymerization.     

A new phosphorescent heteroleptic cuprous complex with a neutral 2‐methylquinolin‐8‐ol ligand: synthesis,structure characterization,properties and TD–DFT calculations

Luminescent Cu^I complexes have emerged as promising substitutes for phosphorescent emitters based on Ir, Pt and Os due to their abundance and low cost. The title heteroleptic cuprous complex, [9,9‐dimethyl‐4,5‐bis(diphenylphosphanyl)‐9H‐xanthene‐κ²P ,P ](2‐methylquinolin‐8‐ol‐κ²N ,O )copper(I) hexafluorophosphate, [Cu(C₁₀H₉NO)(C₃₉H₃₂OP₂)]PF₆, conventionally abbreviated as [Cu(Xantphos)(8‐HOXQ)]PF₆, where Xantphos is the chelating diphosphine ligand 9,9‐dimethyl‐4,5‐bis(diphenylphosphanyl)‐9H‐xanthene and 8‐HOXQ is the N ,O‐chelating ligand 2‐methylquinolin‐8‐ol that remains protonated at the hydroxy O atom, is described. In this complex, the asymmetric unit consists of a hexafluorophosphate anion and a whole mononuclear cation, where the Cu^I atom is coordinated by two P atoms from the Xantphos ligand and by the N and O atoms from the 8‐HOXQ ligand, giving rise to a tetrahedral CuP₂NO coordination geometry. The electronic absorption and photoluminescence properties of this complex have been studied on as‐synthesized samples, whose purity had been determined by powder X‐ray diffraction. In the detailed TD–DFT (time‐dependent density functional theory) studies, the yellow emission appears to be derived from the inter‐ligand charge transfer and metal‐to‐ligand charge transfer (M +L ′)→LCT excited state (LCT is ligand charge transfer).     

[1,3‐Bis(4‐nitrophenyl)triazenido](triphenylphosphine)gold(I)

In the title complex, [Au(C₁₂H₈N₅O₄)(C₁₈H₁₅P)], the coordination geometry about the Au^I ion is linear, with one deprotonated 1,3‐bis(4‐nitro­phenyl)­triazenide ion, [O₂NC₆H₄N=N–NC₆H₄NO₂]⁻, acting as a monodentate ligand (two‐electron donor), and one neutral tri­phenyl­phosphine mol­ecule completing the metal coordination. The triazenide ligand is almost planar (r.m.s. deviation = 0.0767 Å), with the largest interplanar angle being 11.6 (7)° between the phenyl ring of one of the terminal 4‐nitro­phenyl substituents and the plane defined by the N=N—N triad. The Au—N and Au—P distances are 2.108 (5) and 2.2524 (13) Å, respectively. Pairs of mol­ecules generated by centrosymmetry are associated into a supramolecular array via intermolecular C—H⋯O inter­actions, and N⋯C and N⋯O π–π interactions.     

P?C‐Activated Bimetallic Rhodium Xantphos Complexes: Formation and Catalytic Dehydrocoupling of Amine–Boranes

{Rh(xantphos)}‐based phosphido dimers form by P C activation of xantphos (4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene) in the presence of amine–boranes. These dimers are active dehydrocoupling catalysts, forming polymeric [H₂BNMeH]_n from H₃B⋅NMeH₂ and dimeric [H₂BNMe₂]₂ from H₃B⋅NMe₂H at low catalyst loadings (0.1 mol %). Mechanistic investigations support a dimeric active species, suggesting that bimetallic catalysis may be possible in amine–borane dehydropolymerization.     

A new three‐dimensional silver(I) coordination framework with a diamondoid topology constructed from 2‐(pyridin‐4‐yl)‐1H‐imidazole‐4,5‐dicarboxylic acid

The title compound, poly[[μ₄‐5‐carboxy‐4‐carboxylato‐2‐(pyridin‐4‐yl)‐1H‐imidazol‐1‐ido]disilver(I)], [Ag₂(C₁₀H₅N₃O₄)]_n, was synthesized by reacting silver nitrate with 2‐(pyridin‐4‐yl)‐1H‐imidazole‐4,5‐dicarboxylic acid (H₃PyIDC) under hydrothermal conditions. The asymmetric unit contains two crystallographically independent Ag^I cations and one unique HPyIDC²⁻ anion. Both Ag^I cations are three‐coordinated in distorted T‐shaped coordination geometries. One Ag^I cation is coordinated by one N and two O atoms from two HPyIDC²⁻ anions, while the other is bonded to one O and two N atoms from two HPyIDC²⁻ anions. It is interesting to note that the HPyIDC²⁻ group acts as a μ₄‐bridging ligand to link the Ag^I cations into a three‐dimensional framework, which can be simplified as a diamondoid topology. The thermal stability and photoluminescent properties of the title compound have also been studied.     

Stereoselectivity in Diphos Addition to Molybdenum Complex with Pyridine‐2‐thionate (pyS) and η3‐Methallyl Coordinated Ligands

The conformational isomers endo‐ and exo‐[Mo{η³‐C₃H₄(CH₃)}(η²‐pyS)(CO)(η²‐diphos)] (diphos: dppm = {bis(diphenylphosphino)methane}, 2 ; dppe = {1,2‐bis(diphenylphosphino)ethane}, 3 ) are prepared by reacting the double‐bridged pyridine‐2‐thionate (pyS) complex [Mo{η³‐C₃H₄(CH₃)}(CO)₂]₂(η¹:η²:μ‐pyS)₂, 1 with diphos in refluxing acetonitrile. Stereoselectivity of the methallyl, C₃H₄(CH₃), ligand improves the formation of the exo‐conformation of 2 and 3 . Orientations and spectroscopy of these complexes are discussed.     

A monomeric gold(I) carbanion complex with an uncoordinated thioether: [2‐(methylsulfanyl)phenyl](triphenylphosphine)gold(I)

The title compound, [Au(C₇H₇S)(C₁₈H₁₅P)], is conformationally chiral and crystallizes from benzene–hexane as individually enantiopure crystals. This mononuclear compound has the Au^I atom linearly bound to a triphenylphosphine P atom and to a phenyl C atom of a 2‐(methylsulfanyl)phenyl group. The angle at the Au^I atom is 175.9 (2)°. The linear ligand coordination about the Au^I atom has geometric parameters inside the remarkably narrow range found for gold complexes bound by a phosphine ligand and by the ortho‐C atom of a substituted phenyl group. This is the first example of gold(I) attached to a methylsulfanyl aromatic carbanion.     

2‐Ammonio‐5‐chloro‐4‐methylbenzenesulfonate,its 1‐methyl‐2‐pyrrolidone and dimethyl sulfoxide monosolvates and a corrected structure of 2,2′‐(1,4‐phenylene)di(4,5‐dihydroimidazolium) bis(4‐aminobenzenesulfonate) dihydrate

2‐Ammonio‐5‐chloro‐4‐methylbenzenesulfonate, C₇H₈ClNO₃S, (Ia), is an intermediate in the synthesis of lake red azo pigments. The present structure determination from single‐crystal data confirms the results of a previous powder diffraction determination [Bekö, Thoms, Brüning, Alig, van de Streek, Lakatos, Glaubitz & Schmidt (2010). Z. Kristallogr. 225 , 382–387]. The zwitterionic tautomeric form is confirmed. During a polymorph screening, two additional pseudopolymorphs were obtained, viz. 2‐ammonio‐5‐chloro‐4‐methylbenzenesulfonate 1‐methyl‐2‐pyrrolidone monosolvate, C₇H₈ClNO₃S·C₅H₉NO, (Ib), and 2‐ammonio‐5‐chloro‐4‐methylbenzenesulfonate dimethyl sulfoxide monosolvate, C₇H₈ClNO₃S·C₂H₆OS, (Ic). The molecules of (Ib) have crystallographic m symmetry. The 1‐methyl‐2‐pyrrolidone solvent molecule has an envelope conformation and is disordered around the mirror plane. The structure shows hydrogen‐bonded ladders of molecules [graph‐set notation C₂²(6)R₂²(12)] in the [010] direction. The benzene groups of adjacent ladders are also stacked in this direction. A different type of hydrogen‐bonded ladder [graph‐set notation C(6)R₂²(4)R₄⁴(12)] occurs in (Ic). In (Ia), (Ib) and (Ic), the molecules correspond to the zwitterionic tautomer. The structure of the cocrystal of 4‐aminobenzenesulfonic acid with 1,4‐bis(4,5‐dihydroimidazol‐2‐yl)benzene [Shang, Ren, Wang, Lu & Yang (2009). Acta Cryst. E 65 , o2221–o2222] is corrected; it actually contains 4‐aminobenzenesulfonate anions and 2,2′‐(1,4‐phenylene)di(dihydroimidazolium) dications, i.e. 2,2′‐(1,4‐phenylene)di(4,5‐dihydroimidazolium) bis(4‐aminobenzenesulfonate) dihydrate, C₁₂H₁₆N₄²⁺·2C₆H₆NO₃S⁻·2H₂O. Hence, all known structures of aminobenzenesulfonic acid complexes contain ionic or zwitterionic molecules; there is no known structure with a neutral aminobenzenesulfonic acid molecule.     

A Controlled Route to a Luminescent 3 d10–5 d10 Sulfido Cluster Containing Unique AuCu2(μ3‐S) Motifs

The first examples of gold(I) trimethylsilylchalcogenolate complexes were synthesized and their reactivity showcased in the preparation of a novel gold–copper–sulfur cluster [Au₄Cu₄S₄(dppm)₂] (dppm=bis(diphenylphosphino)methane). The unprecedented structural chemistry of this compound gives rise to interesting optoelectronic properties, including long‐lived orange luminescence in the solid state. Through time‐dependent density functional theory calculations, this emission is shown to originate from ligand‐to‐metal charge transfer facilitated by Au???Cu metallophilic bonding.     

Hexanuclear Gold(I) Phosphide Complexes as Platforms for Multiple Redox‐Active Ferrocenyl Units

The synthesis, X‐ray crystal structures, electrochemical, and spectroscopic studies of a series of hexanuclear gold(I) μ₃‐ferrocenylmethylphosphido complexes stabilized by bridging phosphine ligands, [Au₆(P?P)_n(Fc‐CH₂‐P)₂][PF₆]₂ (n=3, P?P=dppm (bis(diphenylphosphino)methane) ( 1 ), dppe (1,2‐bis(diphenylphosphino)ethane) ( 2 ), dppp (1,3‐bis(diphenylphosphino)propane) ( 3 ), Ph₂PN(C₃H₇)‐PPh₂ ( 4 ), Ph₂PN(Ph‐CH₃‐p)PPh₂ ( 5 ), dppf (1,1′‐bis(diphenylphosphino)ferrocene) ( 6 ); n=2, P?P=dpepp (bis(2‐diphenylphosphinoethyl)phenylphosphine) ( 7 )), as platforms for multiple redox‐active ferrocenyl units, are reported. The investigation of the structural changes of the clusters has been probed by introducing different bridging phosphine ligands. This class of gold(I) μ₃‐ferrocenylmethylphosphido complexes has been found to exhibit one reversible oxidation couple, suggestive of the absence of electronic communication between the ferrocene units through the Au₆P₂ cluster core, providing an understanding of the electronic properties of the hexanuclear Au^I cluster linkage. The present complexes also serve as an ideal system for the design of multi‐electron reservoir and molecular battery systems.     

Synthese,Struktur und Reaktivität von η1und η3‐Allyl‐Rhenium‐Carbonylen

Synthesis, Structure, and Reactivity of η¹‐ and η³‐Allyl Rhenium Carbonyls In (η³‐C₃H₅)Re(CO)₄ one CO ligand can be substituted by PPh₃, pyridine, isocyanide and benzonitrile. With 1,2‐bis(diphenylphosphino)ethylene, 1,1′‐bis(diphenylphosphino)ferrocene and 1,2‐bis(4‐pyridyl)ethane dinuclear ligand bridged complexes are obtained. The η³‐η¹ conversion of the allyl ligand occurs on reaction of (η³‐C₃H₅)Re(CO)₄ with the bidendate ligands 1,2‐bis(diphenylphosphino)ethane and 1,3‐bis(diphenylphosphino)propane and with 2,2′‐bipyridine (L–L) which gives the complexes (η¹‐C₃H₅)Re(CO)₃(L–L). By reaction of (η³‐C₃H₅)Re(CO)₄ with bis(diphenylphosphino)methane the allyl group is protonated and under elemination of propene the complex (OC)₃Re(Ph₂PCHPPh₂)(η¹‐Ph₂PCH₂PPh₂) ( 19 ) with a diphosphinomethanide ligand is formed. On heating solutions of (η³‐C₃H₅)Re(CO)₄ and (η³‐C₃H₅)Re(CO)₃(CN‐2,5‐Me₂C₆H₃) ( 5 ) in methanol the methoxy bridged compounds Re₄(CO)₁₂(OH)(OMe)₃ and Re₂(CO)₄(CN‐2,5‐Me₂C₆H₃)₄(μ‐OMe)₂ ( 20 ) were isolated. The crystal structures of (η³‐C₃H₅)Re(CO)₃(CNCH₂SiMe₃) ( 4 ), [(η³‐C₃H₅)(OC)₃Re]₂‐ (μ‐bis‐(diphenylphosphino)ferrocene) ( 8 ), (η¹‐C₃H₅)Re(CO)₃‐ (bpy) ( 14 ), of 19 , 20 and of (OC)₃Re‐[Ph₂P(CH₂)₃PPh₂]Cl ( 16 ) were determined by X‐ray diffraction.     

Ligand‐forced dimerization of copper(I)–olefin complexes bearing a 1,3,4‐thiadiazole core

As an important class of heterocyclic compounds, 1,3,4‐thiadiazoles have a broad range of potential applications in medicine, agriculture and materials chemistry, and were found to be excellent precursors for the crystal engineering of organometallic materials. The coordinating behaviour of allyl derivatives of 1,3,4‐thiadiazoles with respect to transition metal ions has been little studied. Five new crystalline copper(I) π‐complexes have been obtained by means of an alternating current electrochemical technique and have been characterized by single‐crystal X‐ray diffraction and IR spectroscopy. The compounds are bis[μ‐5‐methyl‐N‐(prop‐2‐en‐1‐yl)‐1,3,4‐thiadiazol‐2‐amine]bis[nitratocopper(I)], [Cu₂(NO₃)₂(C₆H₉N₃S)₂], (1), bis[μ‐5‐methyl‐N‐(prop‐2‐en‐1‐yl)‐1,3,4‐thiadiazol‐2‐amine]bis[(tetrafluoroborato)copper(I)], [Cu₂(BF₄)₂(C₆H₉N₃S)₂], (2), μ‐aqua‐bis{μ‐5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine}bis[nitratocopper(I)], [Cu₂(NO₃)₂(C₅H₇N₃S₂)₂(H₂O)], (3), μ‐aqua‐(hexafluorosilicato)bis{μ‐5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine}dicopper(I)–acetonitrile–water (2/1/4), [Cu₂(SiF₆)(C₅H₇N₃S₂)₂(H₂O)]·0.5CH₃CN·2H₂O, (4), and μ‐benzenesulfonato‐bis{μ‐5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine}dicopper(I) benzenesulfonate–methanol–water (1/1/1), [Cu₂(C₆H₅O₃S)(C₅H₇N₃S₂)₂](C₆H₅O₃S)·CH₃OH·H₂O, (5). The structure of the ligand 5‐methyl‐N‐(prop‐2‐en‐1‐yl)‐1,3,4‐thiadiazol‐2‐amine (Mepeta ), C₆H₉N₃S, was also structurally characterized. Both Mepeta and 5‐[(prop‐2‐en‐1‐yl)sulfanyl]‐1,3,4‐thiadiazol‐2‐amine (Pesta ) (denoted L ) reveal a strong tendency to form dimeric {Cu₂L ₂}²⁺ fragments, being attached to the metal atom in a chelating–bridging mode via two thiadiazole N atoms and an allylic C=C bond. Flexibility of the {Cu₂(Pesta )₂}²⁺ unit allows the Cu^I atom site to be split into two positions with different metal‐coordination environments, thus enabling the competitive participation of different molecules in bonding to the metal centre. The Pesta ligand in (4) allows the Cu^I atom to vary between water O‐atom and hexafluorosilicate F‐atom coordination, resulting in the rare case of a direct Cu^I…FSiF₅²⁻ interaction. Extensive three‐dimensional hydrogen‐bonding patterns are formed in the reported crystal structures. Complex (5) should be considered as the first known example of a Cu^I(C₆H₅SO₃) coordination compound. To determine the hydrogen‐bond interactions in the structures of (1) and (2), a Hirshfeld surface analysis has been performed.     

Effects of diphosphine structure on aurophilicity and luminescence in Au(I) complexes

The effects of diphosphine flexibility and bite angle on the structures and luminescence properties of Au(I) complexes have been investigated. A range of diphosphines based on heteroaromatic backbones [bis(2-diphenylphosphino)phenylether (dpephos), 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene (xantphos), and 4,6-bis(diphenylphosphino)dibenzofuran (dbfphos)] has been used to prepare mono- and digold derivatives. A clear relationship between the presence of aurophilic contacts and the emission properties of dinuclear complexes has been observed, with one of the complexes studied, [Au(2)Cl(2)(micro-xantphos)], exhibiting luminescence thermochromism.     

A novel 18‐membered metallocycle in {2,5‐bis[3‐(1H‐1,3‐imidazol‐1‐ylmethyl)phenyl]‐1,3,4‐oxadiazole}dichloridocobalt(II)

The title molecular complex, [CoCl₂(C₂₂H₁₈N₆O)], features a novel 18‐membered Co‐containing metallocycle. The Co^II atom lies in a fairly regular tetrahedral geometry defined by two imidazole N‐atom donors from one 2,5‐bis[3‐(1H‐1,3‐imidazol‐1‐ylmethyl)phenyl]‐1,3,4‐oxadiazole (L) ligand and two chloride anions. The coordinating orientation of the L ligand plays an important role in constructing the metallocycle complex. The complexes form a three‐dimensional supramolecular assembly via nonclassical C—H...Cl and C—H...N hydrogen bonds and π–π interactions.     

1,2‐Di­cyano‐1,2‐bis­(imidazolidine‐2‐thione)­digold(I) and 2,2‐di­cyano‐1,1‐bis­(di­methyl­thio­urea)­digold(I)

Gold(I) cyanide forms complexes with imidazolidine‐2‐thione (etu) and di­methyl­thio­urea (dmtu) with the formula [Au₂(CN)₂L₂], i.e. the title complexes di­cyano‐1κC,2κC‐bis(imidazolidine‐2‐thione)‐1κS,2κS‐digold(I)(Au—Au), [Au₂(CN)₂(C₃H₆N₂S)₂], and di­cyano‐1κ²C‐bis(N,N′‐di­methyl­thio­urea)‐2κ²S‐digold(I)(Au—Au), [Au₂(CN)₂(C₃H₈N₂S)₂]. In the etu complex, two approximately linear (etu)AuCN groups are held together by a weak homopolar Au—Au bond [3.117 (1) Å], with a torsion angle of 61 (3)° between the two groups. In the dmtu complex, an approximately linear Au(dmtu)₂ group is bound to an approximately linear Au(CN)₂ group by a weak heteropolar Au—Au bond [3.091 (1) Å], with a torsion angle of 83 (5)° between the two groups.     

Synthesis and molecular structure of biologically significant bis(1,3‐dimesityl‐4,5‐naphthoquinoimidazol‐2‐ylidene)gold(I) complexes with chloride and dichloridoaurate counter‐ions

Diffraction‐quality single crystals of two gold(I) complexes, namely bis(1,3‐dimesityl‐4,5‐naphthoquinoimidazol‐2‐ylidene)gold(I) chloride benzene monosolvate, [Au(C₂₉H₂₆N₂O₂)₂]Cl·C₆H₆ or [(NQMes)₂Au]Cl·C₆H₆, 2 , and bis(1,3‐dimesityl‐4,5‐naphthoquinoimidazol‐2‐ylidene)gold(I) dichloridoaurate(I) dichloromethane disolvate, [Au(C₂₉H₂₆N₂O₂)₂][AuCl₂]·2CH₂Cl₂ or [(NQMes)₂Au][AuCl₂]·2CH₂Cl₂, 4 , were isolated and studied with the aid of single‐crystal X‐ray diffraction analysis. Compound 2 crystallizes in a monoclinic space group C2/c with eight molecules in the unit cell, while compound 4 crystallizes in the triclinic space group P with two molecules in the unit cell. The crystal lattice of compound 2 reveals C—H…Cl^? interactions that are present throughout the entire structure representing head‐to‐tail contacts between the aromatic (C—H) hydrogens of naphthoquinone and Cl^? counter‐ions. Compound 4 stacks with the aid of short interactions between a naphthoquinone O atom of one molecule and the mesityl methyl group of another molecule along the a axis, leading to a one‐dimensional strand that is held together by strong π–η² interactions between the imidazolium backbone and the [AuCl₂]^? counter‐ion. The bond angles defined by the Au^I atom and two carbene C atoms [C(carbene)—Au—C(carbene)] in compounds 2 and 4 are nearly rectilinear, with an average value of ～174.1 [2]°. Though 2 and 4 share the same cation, they differ in their counter‐anion, which alters the crystal lattice of the two compounds. The knowledge gleaned from these studies is expected to be useful in understanding the molecular interactions of 2 and 4 under physiological conditions.     

Design and Synthesis of Calixarene‐Based Bis‐alkynyl‐Bridged Dinuclear AuI Isonitrile Complexes as Luminescent Ion Probes by the Modulation of Au⋅⋅⋅Au Interactions

Two calixarene‐based bis‐alkynyl‐bridged Au^I isonitrile complexes with two different crown ether pendants, [{calix[4]arene‐(OCH₂CONH‐C₆H₄C≡C)₂}{Au(CNR)}₂] (R=benzo[15]crown‐5 ( 1 ); R=benzo[18]crown‐6 ( 2 )), together with their related crown‐free analogue 3 (R=C₆H₃(OMe)₂‐3,4) and a mononuclear gold(I) complex 4 with benzo[15]crown‐5 pendant, have been designed and synthesized, and their photophysical properties have been studied. The X‐ray structure of the ligand, calix[4]arene‐(OCH₂CONH‐C₆H₄C?CH)₂ has been determined. The cation‐binding properties of these complexes with various metal ions have been studied using UV/Vis, emission, ¹H NMR, and ESI‐MS techniques, and DFT calculations. A new low‐energy emission band associated with Au???Au interaction could be switched on upon formation of the metal ion‐bound adduct in a sandwich fashion.     

Self‐Assembly of a Au16 Ring via Metal–Metal Bonding Interactions

Metal–metal bonding interactions have been employed as an efficient strategy to generate a number of unique gold(I) metallo‐macrocycles with fascinating functions. The self‐assembly, crystal structure and emission property of novel nest‐like tetramer 1₄ , namely, {[Au₄(μ‐dppm)₂(μ‐dctp^2?)](BF₄)₂}₄ ? (CH₃CN)₂ (dppm=bis(diphenylphosphino)methane, dctp^2?=N,N′‐bis(dicarbodithioate)‐2,11‐diaza[3.3]paracyclophane) is reported. The complex has been characterized by single‐crystal X‐ray diffraction analysis, ¹H NMR spectroscopy, ¹³C NMR spectroscopy, and CSI‐MS spectrometry. The aggregate demonstrates the sixteen gold(I) atoms are arranged in a ring with a circumference of 50.011(68) Å generated by Au^I???Au^I attractions. UV/visible and luminescence spectroscopy revealed that this Au^I???Au^I bonded metallo‐macrocycle exhibited yellow phosphorescence.     

Molecular and Crystal Structures of Pentafluorophenyl‐platinum(II) Complexes with Bis(diphenylphosphino)methane,Bis(diphenylarsino)methane and 1,2‐Bis(diphenylarsino)ethane

The X‐ray crystal structures of [PtCl₂(dppm)], [Pt(C₆F₅)₂L] (L = dppm (bis(diphenylphosphino)methane), dpam (bis(diphenylarsino)methane), dpae (bis(diphenylarsino)ethane)) and [PtCl(C₆F₅)(dpae)] show the complexes to be monomeric with chelating dipnictido ligands, and not alternatives with bridging ligands. In [Pt(C₆F₅)₂(dpam)₂], there are two unidentate diarsine ligands in a cis‐arrangement.     

Copper Hydride-Catalyzed Conjugate Reduction-Aldol Addition Domino Reaction of α,β-Unsaturated Carboxylates with Ketones

Copper hydride‐catalyzed conjugate reduction‐intermolecular aldol addition domino reactions were realized using α,β‐unsaturated carboxylates as hydride acceptors and a silane as the reducing reagent. High diastereoselectivities were achieved with 4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene as the ligand and tert‐butyl acrylate as the hydride acceptor.