Synthesis and redox behaviour of the chalcogenocarbonyl dianions [(E)C(PPh(2)S)(2)](2-): formation and structures of chalcogen-chalcogen bonded dimers and a novel selone

The lithium salts of the chalcogenocarbonyl dianions [(E)C(PPh₂S)₂]^2? (E=S ( 4 b ), Se ( 4 c )) were produced through the reactions between Li₂[C(PPh₂S)₂] and elemental chalcogens in the presence of tetramethylethylenediamine (TMEDA). The solid‐state structure of {[Li(TMEDA)]₂[(Se)C(PPh₂S)₂]}—[{Li(TMEDA)}₂ 4 c ]—was shown to be bicyclic with the Li⁺ cations bis‐S,Se‐chelated by the dianionic ligand. One‐electron oxidation of the dianions 4 b and 4 c with iodine afforded the diamagnetic complexes {[Li(TMEDA)]₂[(SPh₂P)₂CEEC(PPh₂S)₂]} ([Li(TMEDA)]₂ 7 b (E=S), [Li(TMEDA)]₂ 7 c (E=Se)), which are formally dimers of the radical anions [(E)C(PPh₂S)₂]^{? .} (E=S ( 5 b ), Se ( 5 c )) with elongated central E? E bonds. Two‐electron oxidation of the selenium‐containing dianion 4 c with I₂ yielded the LiI adduct of a neutral selone {[Li(TMEDA)][I(Se)C(PPh₂S)₂]}—[{LiI(TMEDA)} 6 c ]—whereas the analogous reaction with 4 b resulted in the formation of 7 b followed by protonation to give {[Li(TMEDA)][(SPh₂P)₂CSS(H)C(PPh₂S)₂]}—[Li(TMEDA)] 8 b . Attempts to identify the transient radicals 5 b and 5 c by EPR spectroscopy in conjunction with DFT calculations of the electronic structures of these paramagnetic species and their dimers are also described. The crystal structures of [{Li(TMEDA)}₂ 4 c ], [{LiI(TMEDA)} 6 c ] ? C₇H₈, [Li(TMEDA)]₂ 7 b? (CH₂Cl₂)_0.33, [Li(THF)₂]₂ 7 b , [Li(TMEDA)]₂ 7 c , [Li(TMEDA)] 8 b? (CH₂Cl₂)₂ and [Li([12]crown‐4)₂] 8 b were determined and salient structural features are discussed.     

Octahedral Tin(IV) Complexes of the Chalcogen‐Centered Ligands [EC(PPh2S)2]2– (E = S,Se)

The metathetical reactions between SnBr₄ and Li₂[E'C(PPh₂E)₂] in toluene produce the homoleptic tin(IV) complexes Sn[E′C(PPh₂E)₂]₂ [E = E′ = S ( 1b ); E = S, E′ = Se ( 1c )], which were isolated as red crystals and structurally characterized by X‐ray crystallography. The metrical parameters of these octahedral complexes are compared with those of the all‐selenium analog Sn[E′C(PPh₂E)₂]₂ (E = E′ = Se, 1a ), which was prepared previously by a different route.     

From an Isolable Acyclic Phosphinosilylene Adduct to Donor‐Stabilized SiE Compounds (E=O,S, Se)

Reaction of the arylchlorosilylene‐NHC adduct ArSi(NHC)Cl [Ar=2,6‐Trip₂C₆H₃; NHC=(MeC)₂(NMe)₂C:] 1 with one molar equiv of lithium diphenylphosphanide affords the first stable NHC‐stabilized acyclic phosphinosilylene adduct 2 (ArSi(NHC)PPh₂), which could be structurally characterized. Compound 2 , when reacted with one molar equiv selenium and sulfur, affords the silanechalcogenones 4 a and 4 b (ArSi(NHC)(?E)PPh₂, 4 a : E=Se, 4 b : E=S), respectively. Conversion of 2 with an excess of Se and S, through additional insertion of one chalcogen atom into the Si?P bond, leads to 3 a and 3 b (ArSi(NHC)(?E)‐E‐P(?E)Ph₂, 3 a : E=Se, 3 b : E=S), respectively. Additionally, the exposure of 2 to N₂O or CO₂ yielded the isolable NHC‐stabilized silanone 4 c , Ar(NHC)(Ph₂P)Si?O.     

Five-, six- and eight-membered ring organosilicon chalcogenides of the types Z2(SiMe2)2E (Z = Me2Si, H2C; E = S, Se, Te), Z(SiMe2E)2MR2 (Z = Me2Si, H2C, O; E = S, Se, Te; M = Si, Ge, Sn, R = Me, Ph) and (SiMe2ZSiMe2E)2 (Z = Me2Si, H2C; E = S, Se)

Reactions of ClMe₂Si–Z–SiMe₂Cl (Z = SiMe₂ (1a), CH₂ (1c), O (1e)) with Li₂E (E = S, Se) yielded eight-membered ring compounds (SiMe₂ZSiMe₂E)₂ (3a–d) as well as acyclic oligomers (SiMe₂ZSiMe₂E)_x of different chain lengths. If 1:1 molar mixtures of 1a, 1c or 1e and a diorganodichlorosilane, -germane or -stannane (R₂MCl₂) are reacted with Li₂E (E = S, Se, Te), six-membered ring compounds Z(SiMe₂E)₂MR₂ (4a–7g) are formed exclusively. Five-membered rings Z₂(SiMe₂)₂E (Z = SiMe₂ (8a–c), CH₂ (9a–c); E = S, Se, Te) are obtained starting from the tetrasilane ClMe₂Si–(SiMe₂)₂–SiMe₂Cl (1b) or the disilylethane ClMe₂Si–(CH₂)₂–SiMe₂Cl (1d) by treatment with Li₂E. All products were characterized by multinuclear NMR spectroscopy (¹H, ¹³C, ²⁹Si, ¹¹⁹Sn, ⁷⁷Se, ¹²⁵Te, including coupling constants) and the effects of the different ring sizes towards NMR chemical shifts are discussed.     

Die Kristallstruktur von La2Li1/2Au1/2O4 und bindungschemische Aspekte

The Crystal and the Electronic Structure of La₂Li_1/2Au_1/2O₄ The single crystal X‐ray investigation of the compound La₂Li_1/2Au^III_1/2O₄ yields a T′‐type structure (Nd₂CuO₄) with an ordered distribution of Li^I and Au^III on the sites with square‐planar coordination (space group Ammm; a = 5.768 Å, b = 5.762 Å, c = 12.466 Å; c/a(b) = 2.165; a(Au–O) = 2.013(3) Å). Though Cu^III possesses the same low‐spin d⁸‐configuration as Au^III, La₂Li_1/2Cu_1/2O₄ adopts the ordered T‐structure with strongly elongated CuO₆ octahedra. The electronic and structural causes of the different behaviour are discussed.     

Gold(I) and Gold(III) Trifluoromethyl Derivatives

Trifluoromethylation of AuCl₃ by using the Me₃SiCF₃/CsF system in THF and in the presence of [PPh₄]Br proceeds with partial reduction, yielding a mixture of [PPh₄][Au^I(CF₃)₂] ( 1′ ) and [PPh₄][Au^III(CF₃)₄] ( 2′ ) that can be adequately separated. An efficient method for the high‐yield synthesis of 1′ is also described. The molecular geometries of the homoleptic anions [Au^I(CF₃)₂]^? and [Au^III(CF₃)₄]^? in their salts 1′ and [NBu₄][Au^III(CF₃)₄] ( 2 ) have been established by X‐ray diffraction methods. Compound 1′ oxidatively adds halogens, X₂, furnishing [PPh₄][Au^III(CF₃)₂X₂] (X=Cl ( 3 ), Br ( 4 ), I ( 5 )), which are assigned a trans stereochemistry. Attempts to activate C? F bonds in the gold(III) derivative 2′ by reaction with Lewis acids under different conditions either failed or only gave complex mixtures. On the other hand, treatment of the gold(I) derivative 1′ with BF₃?OEt₂ under mild conditions cleanly afforded the carbonyl derivative [Au^I(CF₃)(CO)] ( 6 ), which can be isolated as an extremely moisture‐sensitive light yellow crystalline solid. In the solid state, each linear F₃C‐Au‐CO molecule weakly interacts with three symmetry‐related neighbors yielding an extended 3D network of aurophilic interactions (Au???Au=345.9(1) pm). The high $\tilde \nu $ _CO value (2194 cm^?1 in the solid state and 2180 cm^?1 in CH₂Cl₂ solution) denotes that CO is acting as a mainly σ‐donor ligand and confirms the role of the CF₃ group as an electron‐withdrawing ligand in organometallic chemistry. Compound 6 can be considered as a convenient synthon of the “Au^I(CF₃)” fragment, as it reacts with a number of neutral ligands L, giving rise to the corresponding [Au^I(CF₃)(L)] compounds (L=CNtBu ( 7 ), NCMe ( 8 ), py ( 9 ), tht ( 10 )).     

Formation and Crystal Structure of the Salt (IC(PPh3)2)2I[I3]·(I2)2 with a new Polyiodide Chain

The reaction of the carbodiphosphorane Ph₃P=C=PPh₃ ( 1 ) with MeI in the presence of iodine gives the oxidation product (IC(PPh₃)₂)₂I[I₃]·(I₂)₂ ( 2 ). In the solid state dimeric units linked by indefinite ···I^?···I₂···I₃^?···I₂···I^?··· chains are found. An additional I···I contact between the cation and the I₂ molecule is formed, amounting to 359.23(5) pm. 2 crystallizes in the monoclinic space group P2/c, with the unit cell dimensions a = 2053.9(1), b = 1011.4(1), c = 1889.8(1) pm; β = 105.21(1)° and Z = 4.     

Bidentate Phosphanyl- and Arsanylboranes

A new class of neutral bidentate ligands with pnictogenyl-functional sites has been obtained. The reaction of tmeda⋅(BH₂I)₂ ( 1 , tmeda=tetramethylethylendiamine) with different phosphanides yields the corresponding bidentate phosphanylboranes tmeda⋅(BH₂PH₂)₂ ( 2 a ), tmeda⋅(BH₂PPh₂)₂ ( 2 b ), and tmeda⋅(BH₂tBuPH)₂ ( 2 c ). This reaction strategy could be further extended to synthesize the first bidentate arsanylborane tmeda⋅(BH₂AsPh₂)₂ ( 3 ). Depending on the substituents on the phosphorus, these compounds form different Au^I complexes, to build either polymeric tmeda⋅(BH₂PH₂AuCl)₂ ( 4 a ), or monomeric tmeda⋅(BH₂PPh₂AuCl)₂ ( 4 b ) products. These compounds form also neutral oligomeric group 13/15 chain-like molecules by coordination to a boron moiety such as tmeda⋅(BH₂PH₂BH₃)₂ ( 5 a ) and tmeda⋅(BH₂AsPh₂BH₃)₂ ( 5 b ). DFT calculations provide insight into the differences between the syntheses of mono- and bidentate pnictogenylboranes.     

Einstieg in die Chemie einfacher Rhenium-Schwefel-Komplexe und -Cluster. Darstellung und Kristall-Struktur von R[ReS4], R′[ReS9], (NH4)4[Re4S22]·2H2O,R′2[Cl2Fe(MoS4)FeCl2]x [Cl2Fe(ReS4)FeCl2]1-x′ R′2 [(ReS4)Cu3l4] und RR′2[(ReS4)Cu5Br7] (R  NEt4; R′  PPh4; x = 0,3, 0,5)

Entry to the Chemistry of Simple Rhenium Sulfur Complexes and Clusters. Preparation and Crystal Structures of R′[ReS₄], R′[ReS₉], (NH₄)₄[Re₄S₂₂]·2H₂O, R′₂[Cl₂Fe(MoS₄)FeCl₂]_1-x, R′₂[(ReS₄)Cu₃I₄] and RR′₂[(ReS₄)Cu₅Br₇] (R ? NEt₄; R′ ? PPh₄, x = 0.3, 0.5) The compounds R[ReS₄] ( 1 ), R′[ReS₉] ( 2 ), (NH₄)₄[Re₄S₂₂]·2 H₂O ( 3 ), R′₂[Cl₂Fe(MoS₄) FeCl₂]_x[Cl₂Fe(ReS₄)FeCl₂] _1-x (x = 0.3 ( 4 ), 0.5), R′₂[(ReS₄)Cu₃I₄] ( 5 ) and R′₂[(ReS₄)Cu₅Br₇] ( 6 ) (R ? NEt₄; R′ ? PPh₄) have been prepared by reaction of perrhenates or rhenium(VII)oxide with S_x^2? solutions (under different conditions) or by reactions of metal-halides with [ReS₄]^?-ions. All compounds have been characterized by complete X- ray structure analysis. For further details see Inhaltsübersicht.     

Metall-Schwefelstickstoff-Verbindungen. 19. Neue Komplexe von CuI mit dem S3N−-Chelatliganden Darstellung und Struktur von [Ph4As][Cu(S3N)(CN)], [(Ph3P)2N][Cu(S3N)(S7N)] und [Ph4As]2[(S3N)Cu(S2O3)Cu(S3N)]

Metal Sulfur-Nitrogen Compounds. 19. Novel Complexes of Cu^I with the S₃N^? Chelate Ligand. Preparation and Structure of [Ph₄As][Cu(S₃N)(CN)], [(Ph₃P)₂N][Cu(S₃N)(S₇N)], and [Ph₄As]₂[(S₃N)Cu(S₂O₃)Cu(S₃N)] In alkaline media S₇NH reacts with Cu salts to yield different products. With Cu(CN) the ion [Cu(S₃N)(CN)]^? is formed, which was isolated as the [Ph₄As]⁺ salt. The crystals are monoclinic, space group P2₁/c, a = 10.499(5), b = 13.418(6), c = 18.032(8) Å, β = 91.84°(3), Z = 4. Besides the known complex ions [Cu(S₃N)₂]^? and [Cu(S₃N)Cl]^? still some more may be obtained when CuCl₂ is reacted with S₇NH: Under special conditions the S₇N ring is partly preserved, and [Cu(S₃N)(S₇N)]^? is formed. Its sparingly soluble [(Ph₃P)₂N]⁺ salt is monoclinic, space group P2₁/n, a = 9.335(6), b = 30.984(11), c = 15.108(8) Å, β = 102.87°(4), Z = 4. Using a longer reaction time a dinuclear complex [(S₃N)Cu(S₂O₃)Cu(S₃N)]^{? ?} results from the reaction of CuCl₂ with S₇NH. The two Cu atoms are bridged by an S atom of the S₂O₃^{? ?} anion. The [Ph₄As]⁺ salt of the dinuclear complex anion is triclinic, space group P1 , a = 11.226(6), b = 12.423(6), c = 19.000(10) Å, β = 76.47°(4), β = 83.98°(4), γ = 84.71°(4), Z = 2. In all these compounds the coordination of Cu^I is trigonal-planar, the S₃N^? chelate group coordinates the Cu in the usual way by two S atoms.     

THE CHEMISTRY OF (ECN)2 (E = S,Se) AND RELATED COMPOUNDS

The psuedohalogens (ECN)₂ (E = S, Se) have been prepared by reaction of AgNCS with bromine and AgNCSe with iodine respectively. (SCN)₂ spontaneously polymerises to give polythiocyanogen a polymer of unknown structure with empirical formula (SCN)_x. A series of late transition metal complexes bearing the ambidentate psuedohalide ligands (ECN) (E = S, Se) have been synthesised. In addition we have prepared a series of late transition metal complexes of the cyanodithioimidocarbonate ion [C₂N₂S₂]^2? and the first transition metal complexes of the cyanodiselenocarbonate ion [C₂N₂Se₂]^2?.     

Synthese und Kristallstrukturen der homoleptischen Phosphaniminato‐Kationen [E(NPPh3)3]+ (E = S,Se, Te) mit Iodid und Triiodid als Gegenionen

Synthesis and Crystal Structures of the homoleptic Phosphoraneiminato Cations [E(NPPh₃)₃]⁺ (E = S, Se, Te) with Iodide and Triiodide Counter Ions N‐Iod‐triphenylphosphaneimine, INPPh₃, reacts with the chalcogenes sulfur, selenium and tellurium in boiling tetrahydrofuran to give the phosphoraneiminato complexes [E(NPPh₃)₃]⁺[¹/₂ I₃^–, ¹/₂ I^–] · THF (E = S ( 1 ), E = Se ( 2 )) and [Te(NPPh₃)₃]⁺I₃^– ( 3 ), respectively. The componds form red crystals which are characterized by IR spectroscopy and by crystal structure determinations. The homoleptic cations [E(NPPh₃)₃]⁺ have pyramidal structures with short EN and PN bond lengths, corresponding to double bonds. 1 : Space group Pa 3, Z = 8, lattice dimensions at –80 °C: a = b = c = 2192.9(1) pm, R₁ = 0.0299. 2 : Space group Pa 3, Z = 8, lattice dimensions at –80 °C: a = b = c = 2202.5(1) pm, R₁ = 0.0357. 3 : Space group Pca2₁, Z = 4, lattice dimensions at –90 °C; a = 1075.8(2); b = 1988.8(4); c = 2437.2(3) pm, R₁ = 0.0443.     

Synthesis and conformational studies of palladium(II) complexes containing [PhP(O)NP(E)Ph]− (E=S or Se)

The ligands [Ph₂P(O)NP(E)Ph₂]⁻ (E=S I; E=Se II) can readily be complexed to a range of palladium(II) starting materials affording new six-membered Pd–O–P–N–P–E palladacycles. Hence ligand substitution reaction of the chloride complexes [PdCl₂(bipy)] (bipy=2,2′-bipyridine), [{Pd(μ-Cl)(L–L)}₂] (HL–L=C₉H₁₃N or C₁₂H₁₃N), [{Pd(μ-Cl)Cl(PMe₂Ph)}₂] or [PdCl₂(PR₃)₂] [PR₃=PPh₃; 2PR₃=Ph₂PCH₂CH₂PPh₂or cis-Ph₂PCH=CHPPh₂] with either I (or II) in thf or CH₃OH gave [Pd{Ph₂P(O)NP(E)Ph₂-O,E}(bipy)]PF₆, [Pd{Ph₂P(O)NP(E)Ph₂-O,E}(L–L)], [Pd{Ph₂P(O)NP(E)Ph₂-O,E}Cl(PMe₂Ph)] or [Pd{Ph₂P(O)NP(E)Ph₂-O,E} (PR₃)₂]PF₆ in good yields. All compounds described have been characterised by a combination of multinuclear NMR [31 P{1 H} and 1 H] and IR spectroscopy and microanalysis. The molecular structures of five complexes containing the selenium ligand II have been determined by single-crystal X-ray crystallography. Three different ring conformations were observed, a pseudo-butterfly, hinge and in the case of all three PR₃ complexes, pseudo-boat conformations. Within the Pd–O–P–N–P–Se rings there is evidence for π-electron delocalisation.     

Gemischtligandkomplexe des Nickel(0) und Kobalt(I) mit anionischen Liganden des Typs E(C6H5)3− (E  Ge,Sn, Pb)

Mixed Ligand Complexes of Nickel(0) and Cobalt(I) with the Anionic Ligands E(C₆H₅)₃^? (E ? Ge, Sn, Pb) Complexes of the general formula M^INi(PPh₃)₃(EPh₃)(THF)_x (E ? Ge[Ia], Sn[Ib], Pb[Ic]) and M^I₃Ni(PPh₃)(EPh₃)₃(THF)_x (E ? Ge[IIa], Sn[IIb]) are formed from (Ph₃P)₂Ni(C₂H₄) by substitution with M^IEPh₃. The analogous complexes of the ligand SiPh₃^? could not be prepared, because of the formation of SiPh₄ from LiSiPh₃ and coordinated PPh₃. Attempts to synthesize a nickel(II) complex of the ligand SnPh₃^? had no success, only possible decomposition products of these compounds, like (nBu₂PPh)₂Ni^II(Ph)Cl and Na_xNi°(PPh₃)_4?x(SnP₄)_x(THF)_Y, were isolated. NaCo^I(PPh₃)₂(SnPh₃)₂(THF)₇ (IV) was prepared by the reaction of Co(PPh₃)₃Cl and NaSnPh₃. ¹H-NMR and ¹¹⁹Sn Mössbauer spectra show a higher donor action of SnPh₃^? in IIb than in Ib. This causes a stronger π-back donation Ni → P in the case of IIb. IV is a paramagnetic compound, the vis-spectrum is discussed using simple crystal field theory.     

Gold clusters: synthesis and characterization of [Au8(PPh3)7(CNR)]2+, [Au9(PPh36(CNR2]3+ and [Au11(PPH37(CNR)2O]2+ and their reactivity towards amines. The crystal structure of [Au11(PPh3)7(CN-i-Pr)2I](PF6)2

In the reactions of [Au₈(PPh₃)₇]²⁺, [Au₈(PPh₃)₈]²⁺ and [Au₉(PPh₃)₈]³⁺ with RNC (R = isopropyl and t-butyl) in dichloromethane [Au₈(PPh₃)₇CNR]²⁺ is initially, and is then converted into [Au₉(PPh₃)₆(CNR)₂]³⁺ via various intermediates. [Au₉(PPh₃)₆(CNR)₂]³⁺ reacts with I⁻ at low temperature (−78°C) in methanol to yield [Au₁₁(PPh₃)₇(CNR)₂I]²⁺, but when the reaction is carried out at room temperature Au₁₁ (PPh₃)₆(CNR)I₃ is formed. The cluster compounds have been characterised by elemental analysis, ³¹P{¹H} NMR, conductivity measurements, IR and ¹⁹⁷Au Mössbauer spectroscopy. The reactions of the clusters with amines to form carbene clusters are very slow, and the reasons for this are considered.The structure of [Au₁₁C₁₃₄H₁₁₂IN₂P₇](PF₆ was determined by X-ray diffraction. M_r = 3796.39 cubic, space group 143_d, a 37.955(12) Å, V 54677.2 ų, Z = 16, D_c = 2.21 Mg m⁻³, Mo-K_α radiation (graphite crystal monochromator, λ 0.71069 Å), μ(Mo-K_α) 125.2 cm⁻¹, F(000) = 33510.3, T 293 K. Final conventional R-factor = 0.048, R_w = 0.062 ofr 1867 unique reflections and 198 variables. The Au-skeleton is the same as in Au₁₁(PPh₃)₈I₃ having C_3v symmetry with one central and 10 peripheral Au atoms.     

Metallchelate ungesättigter geminaler Dichalcogenoliganden mit gemischten S,Se-Ligatoren Kristall- und Molekülstruktur von Tetra-n-butylammonium-bis(1,1-dicyanoethylen-2,2-thioselenolato)nickelat(II), [(n-C4H9)4N]2[Ni(SSeC?C(CN)2)2]

Metal Chelates of Unsaturated Geminal Dichalcogeno Ligands Containing S as well as Se Ligators. Crystal and Molecular Structure of Tetra-n-butylammonium-bis(1,1-dicyanoethylene-2,2-thioselenolato)nickelate(II), [(n-C₄H₉)₄N]₂[Ni(SSeC? C(CN)₂)₂] Synthesis and properties of chelates of the thioseleno ligands 1,1-dicyanoethylene-2,2-thioselenolate (bis-chelates with Ni²⁺, Pd²⁺, Pt²⁺, Cu²⁺, Au³⁺, Zn²⁺, Cd²⁺, Se²⁺, Te²⁺, UO₂²⁺; tris-chelate mit Cr³⁺, Fe³⁺, Co³⁺, Rh³⁺, In³⁺; 1:1-chelate mit Cu⁺, Au⁺), cyanthioselenocarbimate (bis-chelates with Ni²⁺, Pd²⁺) and 0-β-methoxyethyl-thioselenocarbonate (bis-chelates with Ni²⁺, Pd²⁺, Pt²⁺, Zn²⁺; tris-chelate mit Cr³⁺, Co³⁺, Rh³⁺) are reported. The X-ray crystal structure of [(n-C₄H₉)₄N]₂[Ni(SSeC? C(CN)₂)₂] shows a planar NiS₂Se₂ arrangement. From the space group P2₁/c (a = 14,043(1) Å, b = 8.704(1) Å, c = 20.647(2) Å, β = 108.56(1)°) and Z = 2 follows a trans position of the thioseleno ligands. The same magnitude of the C–S and C–Se distance refers to a hindrance of the equalization of the bonding in the chelate. The structure is compared with those of similar compounds.     

Bimetallic Au2Cu6 Nanoclusters: Strong Luminescence Induced by the Aggregation of Copper(I) Complexes with Gold(0) Species

The concept of aggregation‐induced emission (AIE) has been exploited to render non‐luminescent Cu^ISR complexes strongly luminescent. The Cu^ISR complexes underwent controlled aggregation with Au⁰. Unlike previous AIE methods, our strategy does not require insoluble solutions or cations. X‐ray crystallography validated the structure of this highly fluorescent nanocluster: Six thiolated Cu atoms are aggregated by two Au atoms (Au₂Cu₆ nanoclusters). The quantum yield of this nanocluster is 11.7 %. DFT calculations imply that the fluorescence originates from ligand (aryl groups on the phosphine) to metal (Cu^I) charge transfer (LMCT). Furthermore, the aggregation is affected by the restriction of intramolecular rotation (RIR), and the high rigidity of the outer ligands enhances the fluorescence of the Au₂Cu₆ nanoclusters. This study thus presents a novel strategy for enhancing the luminescence of metal nanoclusters (by the aggregation of active metal complexes with inert metal atoms), and also provides fundamental insights into the controllable synthesis of highly luminescent metal nanoclusters.     

Photochemical reactions of M(CO)6 (M = Cr,Mo, W) with Ph2P(S)P(S)Ph2

New complexes {M(CO)₄[Ph₂P(S)P(S)Ph₂]} (M = Cr, Mo and W), (1a)–(3a), [(1a), M = Cr; (2a), M = Mo; (3a), M = W] and {M₂(CO)₁₀[-Ph₂P(S)P(S)Ph₂]} (M = Cr, Mo, W), [(1b)–(3b) [(1b), M = Cr; (2b), M = Mo; (3b), M = W]] have been prepared by the photochemical reaction of M(CO)₆ with Ph₂P(S)P(S)Ph₂ and characterized by elemental analyses, f.t.-i.r. and ³¹P-(¹H)-n.m.r. spectroscopy and by FAB-mass spectrometry. The spectra suggest cis-chelate bidentate coordination of the ligand in {M(CO)₄[Ph₂P(S)P(S)Ph₂]} and cis-bridging bidentate coordination of the ligand between two metals in (M = Cr, Mo and W).     

Deprotonierte Dithiocarbaminsäureester als Thiolat-S-Donor-Liganden. Strukturen von Ph(H)NC(S)SMe,Co(PhNC(S)SMe)3 und Cu6(PhNC(S)SMe)6

Deprotonated Dithiocarbamic Acid Esters as Thiolate S-Donor Ligands. Structures of Ph(H)NC(S)SMe, Co(PhNC(S)SMe)₃, and Cu₆(PhNC(S)SMe)₆ The reaction of N-phenyl-S-methyldithiocarbamate, PhN(H)C(?S)SMe, ( 1 ) with cobalt(II) and copper(II) salts yields the monomeric compound Co^III(PhNC(S)SMe)₃ ( 2 ) and the hexameric compound Cu₆^I(PhNC(S)SMe)₆ ( 3 ). These complexes contain the negatively charged imino-thiolate ligand PhN?C(? S)SMe, which has been formed by deprotonation of 1 . The crystal structures of 1 – 3 have been determined. 1 forms centrosymmetrical dimers through N? H …? S bridge bonds, the conformation in the solid state and in solution is Z,E′. Co^III shows in 2 a trigonal-antiprismatic coordination, with the ligands acting as N,S-chelates. 3 contains an octahedral Cu₆-core with Cu …? Cu-distances ranging from 276.3(5) to 305.7(4) pm. Each copper center is trigonally coordinated to one nitrogen and two sulfur atoms of three different ligands. Crystal data: 1 , triclinic, space group P1 , a = 590.5(6), b = 869.0(1), c = 968.5(9) pm, α = 67.29(8), β = 78.44(8), γ = 81.64(9)°, Z = 2, 1 775 reflections, R(R_w) = 0.0317(0.032). 2 , orthorhombic, space group Pbca, a = 978.0(2), b = 1 842.9(4), c = 3 059.7(6) pm, Z = 8, 1 129 reflections, R(R_w) = 0.0997(0.0886). 3 , monoclinic, space group P2₁/c, a = 1 363.1(3), b = 1 342.8(3), c = 1 671.9(3) pm, β = 103.48°, Z = 2, 1 374 reflections, R(R_w) = 0.0708(0.0617).     

Chalcogenido-Dimethylgallates and -Indates DMPyr2[Me2M(μ2−E)]2 (M=Ga,In; E=S,Se): Building Blocks for Higher and Lower Order Chalcogenidoindates

Metalation of the anions in the ionic liquids DMPyr[SH] and DMPyr[SeH] (DMPyr=1,1-dimethylpyrrolidinium) by trimethylgallium and trimethylindium is investigated. The reaction proceeds via pre-coordination of [EH]⁻, methane elimination and formation of an unprecedented series of chalcogenido metalates DMPyr₂[Me₂M(μ₂−E)]₂ (M=Ga, In; E=S, Se). These show the presences of dinuclear dianions with four-membered ring structures displaying highly nucleophilic bridging chalcogenide ligands in their crystallographically determined molecular structures. Some representative reactions of these building blocks with amphoteric electrophiles were studied: Addition of two equivalents of E(SiMe₃)₂ (E=S, Se) to the indates DMPyr₂[Me₂In(μ₂−S)]₂ and DMPyr₂[Me₂In(μ₂−Se)]₂ leads to a cleavage of the ring, E silylation and formation of mononuclear, monoanionic indates DMPyr[Me₂In(SSiMe₃)₂], DMPyr[Me₂In(SeSiMe₃)₂], and even a mixed sulfido-selenido dimethylindate DMPyr[Me₂In(SSiMe₃)(SeSiMe₃)]. Reaction of DMPyr₂[Me₂In(μ₂−S)]₂ with two equivalents of Lewis acid Me₃In leads to charge delocalization, ring expansion and formation of six-membered ring DMPyr₃[Me₂In(μ₂−S−InMe₃)]₃. The latter is a key intermediate in the formation of dianionic sulfidoindate DMPyr₂[(Me₂In)₆(μ₃−S)₄] displaying an unusual inverse heteroadamantane cage structure with four capping sulfido ligands.