Synthesen und Strukturen von Übergangsmetall‐Komplexen mit Dithiophosphinato‐ und Trithiophosphonato‐Liganden

Syntheses and Structures of Transition Metal Complexes with Dithiophosphinato and Trithiophosphinato Ligands The reactions of MnCl₂ with Ph₂P(S)(SSiMe₃) produced [Mn(S₂PPh₂)₂(thf)₂] ( 1 ) and [Mn(S₂PPh₂)₂(dme)] ( 2 ) (DME = 1,2‐Dimethoxyethane). The compounds [Co₆(S₃PPh)₂(μ⁴‐S)₂(μ³‐S)₂(PPh₃)₄] ( 3 ), [Co₂(S₃PPh)₂(PPh₃)₂] ( 4 ), [Ni(S₂PPh)(PPhEt₂)₂] ( 5 ), [Ni(S₃PPh)(PPhEt₂)₂] ( 6 ) and [Cu₄(S₃PPh)₂(dppp)₂] ( 8 ) [dppp = 1,3‐Bis(diphenylphosphanyl)propane] were obtained from reactions of first‐row transition metal halides with PhP(S)(SSiMe₃)₂ in the presence of tertiary phosphines. In a reaction of PhP(S)(SSiMe₃)₂ with PhPEt₂ PhPEt₂PS₂Ph ( 7 ) was isolated. All compounds were characterized by X‐ray crystallography.     

Dipodal ferrocene-based adsorbate molecules for self-assembled monolayers on gold

1,1'-Difunctionalised ferrocene derivatives have been studied, which contain groups suitable for chemisorption on gold substrates, namely -NC, -PR(2) as well as a range of sulfur-containing units like -NCS, -SR, and thienyl. Thin films on gold have been fabricated from solution with most of these adsorbate species. Film thickness, composition and structure were investigated primarily by X-ray photoelectron and near-edge X-ray absorption fine-structure spectroscopy. The quality of self-assembled monolayers fabricated from 1,1'-diisocyanoferrocene (1) and 1,1'-diisothiocyanatoferrocene (2) turned out to be superior to that of films based on the other adsorbate species investigated. In addition to the surface coordination behaviour of 1 towards gold substrates, relevant aspects of the molecular coordination chemistry of 1 have also been addressed, including the synthesis and characterisation of [(mu-1){Cr(CO)(5)}(2)], [Ag(2)(mu-1)(2)](NO(3))(2) x H(2)O and [(mu-1)(AuCl)(2)]. The crystal structure of the gold complex is governed by aurophilic interactions and can be taken as a model for the arrangement of 1 in self-assembled monolayers on gold.     

Polymeric arrangements of P-Se anions and a first insight into their reactivity

The reactions of the P/Se-precursor Woollins' reagent [PhP(Se)mu-Se]2 with alkali-metal salts offer new perspectives for the synthesis of metal aggregates containing P-Se anions. Depending on the alkali-metal thiolates polymeric arrangements of [PhPSe3]2- or [PhPSe2Se-SeSe2PPh]2- dianions are observed and the mechanisms of their formation described.     

Synthesis of crown ether complexes of alkali-metallated organophosphine oxides and insertion reactions with isonitriles

The synthesis and crystal structures of the alkali-metallated organophosphine oxides [{Ph₂P(O)CH₂}K · 18-crown-6] (1) and [{Ph₂P(O)CH₂}Na · 15-crown-5] (2) are reported. In addition the insertion reaction of an isonitrile into the C-Li bond of [{Ph₂P(O)CH₂}Li] is reported and the crystal structure of the resulting tetrameric complex [Ph₂P(O)CHCHN(Cy)Li]₄ (3) (Cy = Cyclohexyl) described.     

Synthesis,Characterization and X‐ray Structures of AMTT‐Type Schiff bases and two CuI Complexes (AMTT= 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione)

The reaction of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AMTT) with 4‐methylbenzaldehyde and 4‐methoxybenzaldehyde in ethanol led to the iminic derivatives ‐4‐(4‐methylbenzylideneamino)‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)thione ( L1 ) and 4‐(4‐methoxybenzyl‐ideneamino)‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione ( L2 ). The reaction of L1 with CuCl in the presence of triphenylphosphane as co‐ligand in methanol/chloroform solution gave the Cu^I complex containing L1 , [Cu( L1 )(PPh₃)₂Cl]·0.5CH₃OH·0.25CHCl₃ ( 1 ). Treatment of L2 with the same metal salt in a molar ratio of 1:1 in methanol and further addition of a solution of PPh₃ in chloroform led to the complex [Cu( L2 )(PPh₃)₂Cl]·2.5CHCl₃ ( 2 ). The complexes and L1 were characterized by IR and NMR spectroscopy as well as by X‐ray diffraction studies. In both complexes, the Schiff base ligand is coordinated to the copper ion through its sulfur atom. The other coordination sites around the copper ion are occupied by two triphenylphosphane molecules and one chloride ion. Therefore, each Cu^I ion is in a distorted tetrahedral environment. Crystal data for L1 at ?100 °C: space group P2₁/n with a = 720.5(1), b = 1140.6(1), c = 1426.3(2) pm, β = 91.25(1)°, Z = 4, R₁ = 0.03, for 1 at ?120 °C : space group with a = 1286.3(1), b = 1740.3(1), c = 2060.2(1) pm, α = 79.085(6), β = 83.827(5), γ = 76.688(6)°, Z = 4, R₁ = 0.0649 and for 2 at ?80 °C : space group with a = 1183.7(2), b = 1370.1(2), c = 1812.1(3) pm, α = 85.69(2), β = 88.52(2), γ = 64.89(2)°, Z = 2, R₁ = 0.0488.     

A close look at short C-CH3...potassium contacts: synthetic and theoretical investigations of [M2Co2(mu3-OtBu)2(mu2-OtBu)4(thf)n] (M = Na, K, Rb, thf = tetrahydrofuran)

Agostic interactions of the type Si-CH3M+ (M = alkali metal) are frequently mentioned in discussions of solid-state structures of trimethylsilyl compounds and the purpose of this work was to elucidate if they also exist in the related tert-butyl species by using density functional theory. The compounds [M2Co2(mu3-OtBu)2(mu2-OtBu)4(thf)n] (M = Na, n = 2; M = K, n = 0; M = Rb, n = 1) have been synthesised and their crystal structures determined. Close contacts of methyl groups with K atoms are observed in the solid-state structure of [K2Co2(mu3-OtBu)2(mu2-OtBu)4], and calculations of the rotational barrier of a tert-butoxy group about the axis through the C-O bond were performed. It was shown that apparent short C-CH3K distances are in this case a consequence of the packing in the extended solid-state structure.     

Synthesis and Characterization of the Quaternary Thio­aluminogermanates A(AlS2)(GeS2) (A = Na,K)

The quaternary thioaluminogermanates Na(AlS₂)(GeS₂) ( 1 ) and K(AlS₂)(GeS₂) ( 2 ) crystallize in the tetragonal space group I4/mcm (no. 140) with unit cell parameters a = 7.4274(11) Å, c = 5.8560(12) Å for Na(AlS₂)(GeS₂) and a = 7.8826(2) Å, c = 5.8642(4) Å for K(AlS₂)(GeS₂). The crystal structure comprises of one‐dimensional [(AlS₂)(GeS₂)]^– anionic chains with Al and Ge sharing the tetrahedral site. The alkali metal cations fill the square antiprismatic voids between chains. Both 1 and 2 are semiconductors with bandgap of around 3.6 eV and 3.5 eV, respectively.     

High-efficiency (7.2%) flexible dye-sensitized solar cells with Ti-metal substrate for nanocrystalline-TiO2 photoanode

High-efficiency flexible dye-sensitized solar cells were fabricated with a Ti-metal foil substrate for photo anode and using a Pt-electrodeposited counter electrode on ITO/polyethylene naphthalate (ITO/PEN); these devices were characterized by incident photon-to-current efficiency (IPCE), optical transmittance and electrical impedance spectroscopy.