Komplexe mit kohlenstoffsulfiden und -seleniden als liganden: IV. Ein- und zweikernige rhodium—CS2-komplexe und kristallstruktur eines RhSCSC-heterocyclus

The complexes C₅H₅Rh(PMe₃)CS₂(II) and C₅H₅Rh(PMe₂Ph)CS₂(III) are formed in excellent yields in the reaction of C₅H₅Rh(C₂H₄)PR₃(PR₃ = PMe₃, PMe₂Ph) with CS₂ in benzene. The CS₂ ligand in II and III is dihapto-bonded and at least in III is rigid. II reacts with Cr(CO)₅THF and C₅H₅Mn(CO)₂THF to give the binuclear complexes C₅H₅(PMe₃)Rh(SCS)Cr(CO)₅ (IV) and C₅H₅- (PMe₃)Rh(SCS)Mn(CO)₂C₅H₅ (V) in which the CS₂ molecule bridges two different metal atoms. In the reaction of C₅H₅Rh(C₂H₄)PMe₃ and CS₂ under certain conditions a second product of C₅H₅Rh(PMe₃)C₂S₄ (VI) is formed. The cyrstal structure shows that in this complex a five-membered RhSCSC heterocyclic ring is present.     

Die thermische zersetzung von metallorganischen wolfram- und molybdänkomplexen des typs M(CO)nCl2L2

The thermal decomposition reactions of the M(CO)_nCl₂L₂ type complexes M: W, Mo; n: 2, 3; L: P(C₆H₅)₃, As(C₆H₅)₃, OP(C₆H₅)₃ were studied. It was found that the tricarbonyl complexes split off the CO groups in 2+1 mole ratio, and after that the L ligands in a multi-step reaction. The splitting-off of the CO ligands might be a one-step (OPph₃), or a two-step process (Pph₃) in the case of the dicarbonyl compounds. The following thermal stability order is given: W>Mo; Pph₃>Asph₃>OPph₃; dicarbonyl ≈ tricarbonyl (ph - C₆H₅).     

Basische metalle : IX. Synthese und kristallstruktur von C5H5Co(PMe3)CS2. Reaktionen zu zweikernkomplexen mit Co(SCS)Cr- und Co(SCS)Mn-Brückenbindungen

C₅H₅Co(PMe₃)CS₂ (IV) is formed in practically quantitative yield in the reaction of C₅H₅Co(PMe₃)₂ (I) or the heterobinuclear complex C₅H₅(PMe₃)Co(CO)₂Mn(CO)C₅H₄Me (III) with CS₂. The crystal structure shows that the carbon disulfide bonds as a dihapto ligand through the carbon and one sulfur atom (S(2)) (CoC = 1.89, CoS(2) = 2.24 Å, S(2)CS(1) = 141.2°). The two CS bond lengths in IV (CS(2) = 1.68, CS(1) =1.60 Å) are greater than in free CS₂ (1.554Å) which is in agreement with the strong π-acceptor character of h²-CS₂ as shown in the spectroscopic data. IV reacts with Cr(CO)₅THF and C₅H₅Mn(CO)₂THF to give the complexes C₅H₅(PMe₃)Co(SCS)Cr(CO)₅ (V) and C₅H₅(PMe₃)Co(SCS)Mn(CO)₂C₅H₅ (VI) respectively, in which the sulfur atom S(1) that is not bound to cobalt coordinates to the 16-electron fragments Cr(CO)₅ and Mn(CO)₂C₅H₅. The spectroscopic data of IV, V and VI are discussed.     

Transition metal derivatives of 1,1′-dichloroferrocene

Complexes of the general formula [Cl₂Fc] _nML, (Cl₂Fc = C1C₅H₄FeC₅H₃Cl; ML = Fe(CO)₂C₅H₅, AuP(C₆H₅)₃, Mn(CO)₅ or Ir(CO)[P(C₆H₅)₃]₂ when n = 1; ML = Ti(C₅H₅)₂ when n = 2) have been prepared from a salt elimination reaction between 1,1′-dichloro-2-lithioferrocene and transition metal halide complexes. Spectroscopic properties of the compounds are reported. The titanium complex exists in meso and dl forms.     

A DFT study of Lp···π/halogen bond competition in complexes of perhalogenated alkenes with oxygen/nitrogen containing simple molecules

The possible noncovalent lone pair‐π/halogen bond (lp···π/HaB) complexes of perhalogenated unsaturated C₂Cl_nF_4?n (n = 0–4) molecules with four simple molecules containing oxygen or nitrogen as electron donor, formaldehyde (H₂CO), dimethyl ether (DME), NH₃, and trimethylamine (TMA), have been systematically examined at the M062X/aug‐cc‐pVTZ level. Natural bond orbital (NBO) analysis at the same level is used for understanding the electron density distributions of these complexes. The progressive introduction of Cl atom on C₂Cl_nF_4?n influences more on the lp···π complexes over the corresponding HaB ones. Within the scope of this study, gem‐C₂Cl₂F₂ is the best partner molecule for lp···π interaction with the simple molecules, coupled with the greatest interaction energy (IE) and second‐order orbital interaction [E(2) value], whereas C₂F₄ is the poorest one. The C₂Cl₃F·H₂CO and C₂Cl₄·H₂CO complexes exhibit reverse lp···π bonding, while the Z/E‐C₂Cl₂F₂·NH₃, C₂Cl₃F·NH₃ and C₂Cl₄·NH₃ complexes perform half‐lp···π bonding according to the NBO analysis. The lp···π interaction involving the oxygen/nitrogen and the π‐hole of C₂Cl_nF_4?n overwhelms the HaB involving the oxygen/nitrogen and the σ‐hole of the Cl atom. The electron‐donating methyl groups contribute significantly to the two competitive interactions, therefore, DME and TMA engage stronger in the partner molecules than H₂CO and NH₃. Our theoretical study would be useful for future experimental investigation on noncovalent complexes. © 2016 Wiley Periodicals, Inc.     

Co(III) complexes with optically active bis(menthane), pinano-para-menthane, carano-para-menthane, and bis(carane) propylenediaminodioximes

Novel optical ligands bis(menthane) (H₂L¹), pinano-para-menthane (H₂L²), and carano-para-menthane (H₂L³) propylenediaminodioximes are obtained. Diamagentic Co(III) complexes of the composition Co(HL¹)Cl₂ (I), Co(HL²)Cl₂ (II), Co(HL³)Cl₂ (III), and Co(HL⁴)Cl₂ · H₂O(IV) are synthesized by reactions of CoCl₂ with H₂L¹, H₂L², H₂L³ and bis(carane) propylenediaminodioxime (H₂L⁴) in ethanol in air. The crystal and molecular structures of compound I is determined by X-ray diffraction analysis. The crystals are monoclinic with the unit cell parameters a = 7.8385(3) Å, b = 11.4074(6) Å, c = 14.9509(6) Å, β = 104.278(2)°, V = 1295.57(10) ų, Z = 2, ρ(calcd) = 1.367 g/cm³, F(000) = 564, M = 533.41, space group P2₁. The crystal structure of complex I consists of individual mononuclear molecules. The Co³⁺ ion coordinates four N atoms of tetradentate cycle-forming anionic ligand and two Cl atoms. The coordination polyhedron of Cl₂N₄ is a distorted octahedron. The ¹³C and ¹H NMR spectra of the complexes synthesized confirm coordination of four N atoms of a ligand.     

The coordination and activation of carbon disulfide in binuclear rhodium complexes

The reaction of trans-[RhCl(CO)(DPM)]₂ (DPM = Ph₂PCH₂PPh₂) with CS₂ yields an interesting series of CS₂ complexes culminating in the condensation of two CS₂ molecules yielding the unusual, asymmetric species [Rh₂Cl₂(CO)- (C₂S₄)(DPM)₂]. This novel C₂S₄ species is also produced in the reaction of [Rh₂Cl₂(μ-CO)(DPM)₂] with CS₂. The structural determination of the C₂S₄ complex indicates that the C₂S₄ moiety bridges the rhodium atoms such that it forms a R$\text{hSCSC}$ metallocycle with one rhodium atom while simultaneously bonding through a sulfur atom to the second rhodium atom forming a R$\text{hCSR}$h metallocycle. A scheme for the reactions of the above complexes with CS₂ is presented.     

Dehalogenative aromatization of perchlorofluoroalicyclic compounds C6Cl6F6, C10Cl8F8 and C5Cl4F5N in the vapour phase or in solution

Dehalogenation of perhalogenated cyclohexanes C₆Cl₆F₆, 1-azacyclohexenes C₅Cl₄F₅N and bicyclo[4.4.0]dec-1(6)-enes C₁₀Cl₈F₈ in the vapour phase over iron filings at 350-500 °C and in solution with Zn and additivities (Cu, NiCl₂·6H₂O + bpy) at 80 °C (heterogeneous reaction) or with P(NEt₂)₃ at 20 °C (homogeneous reaction) was studied. In all cases, perfluoroarenes, chloroperfluoroarenes and dichloroperfluoroarenes (benzenes, naphthalenes and pyridines) were obtained in good overall yield.     

Reactions of some fluoroaromatics with the ethoxide anion

The reactions of sodium ethoxide in ethanol with various fluoroaromatics, C₆F_6?nH_n, C₆F_5?nH_nNO₂, C₆F₅X (X = CF₃, C₆F₅, COCH₃, CH₂Br), C₆Cl₆ and $\text{m}$H₂C₆Cl₄ have been studied. Partial substitution of the aromatic halogen was observed. The new products have been characterized by elemental analysis, NMR (H?1 and F?19), infrared and mass spectroscopy.     

Synthesis and structure of r—p-bridged trinuclear heterometallic clusters of manganese and chromium

Complexes of the type L_nMPRCl₂ (L_nM  (CO)₅Cr or C₅H₅(CO)₂Mn), on treatment with C₅H₅Co(CO)₂, undergo dehalogenation giving mixed metal clusters, L_nMPR[CoC₅H₅(CO)]₂. The molecular structure of (C₅H₅)₃Co₂Mn(CO)_4±PCH₂C₆H₅ is described. Monoclinic, space group P2₁/c with a 9.579, b 14.338, c 17.650 Å, Z = 4.     

Chlorinated organic derivatives containing MoHg and WHg bonds: Importance of the steric effects in their stabilization

A series of MoHg and WHg bonded complexes [RHgM(CO)₃Cp], (R = 2,4,6-C₆H₂Cl₃,2,3,5,6-C₆,HCl₄ and C₆Cl₅) have been prepared from ClHgR and the salts Na[M(CO)₃)Cp]. When R contains only one ortho chlorine atom (R = 2,5-C₆H₃Cl₂, 2,3,4-C₆H₂Cl₃ and 2,3,4,5-C₆HCl₄) a symmetrisation process occurs to give the corresponding HgR₂ and Hg[M(CO)₃Cp)₂2. These results indicate that steric effects are very important in the formation of compounds containing molybdenum- or tungsten—mercury bonds. Complexes of the type [(C₆Cl₅)HgM(CO)₂(PPh₃)Cp] (M = Mo and W) are obtained from [(C₆Cl₅)HgM(CO)₃Cp] and PPh₃ in boiling ethanol.     

Synthesis, characterization and structural studies of diorganotin(IV) complexes with Schiff base ligand salicylaldehyde isonicotinylhydrazone

Eight diorganotin(IV) complexes of salicylaldehyde isonicotinylhydrazone (H₂SalN) R₂Sn(SalN) R = t-Bu 1, Ph 2, PhCH₂3, o-ClC₆H₄CH₂4, p-ClC₆H₄CH₂5,m-ClC₆H₄CH₂6,o-FPhCH₂7, p-FC₆H₄CH₂8 were prepared. All complexes 1-8 have been characterized by elemental, IR, ¹H, ¹³C and ¹¹⁹Sn NMR analyses. The crystal structures of H₂SalN and complex 1 were determined by X-ray crystallography diffraction analyses. Studies show that H₂SalN is a tridentate planar ligand. For complex 1, the tin atom lies in this plane and forms a five- and six-membered chelate ring with the tridentate ligand. A comparison of the IR spectra of the ligand with those of the corresponding complexes, reveals that the disappearance of the bands assigned to carbonyl unambiguously confirms that the ligand coordinate with the tin in the enol form.     

Oxidative addition - reductive elimination sequences in the photochemistry of some bis(phosphine)platinum complexes

The photolysis of [L₂Pt(C₂H₄)] (L = PPh₃, P(p-C₆H₄CH₃)₃ complexes in halocarbon solvents (CH₂Cl₂, CH₂Br₂) gives C₂H₄ and the coordinatively unsaturated species [L₂Pt]. Photolysis of platinum metallacycles [L₂Pt(CH₂)₄] (L = PPh₃, P(n-Bu)₃) generates alkanes, alkenes and [L₂Pt]. The [L₂Pt] centers are very reactive, and under prolonged photolysis undergo oxidative addition of CH₂Cl₂ forming the trans-[L₂Pt(CH₂Cl)Cl] complexes. Under appropriately controlled conditions the trans complexes isomerize to cis species before bimolecular C₂H₄ elimination occurs and [L₂PtCl₂] is formed as the final product. The oxidative addition-reductive elimination mechanism is discussed on the basis of spin-trapping experiments, quantum yield values, and the sensitivity to radical inhibitors and to solvents.     

Synthese von Oxovanadium(V)‐halogeno‐Komplexen der tripodalen Sauerstoffliganden LR— = [η5‐(C5H5)Co{PR2(O)}3]—, R = OMe,OEt

Syntheses of Oxovanadium(V) Halide Complexes Stabilized with Tripodal Oxygen Ligands L_R^— = [η⁵‐(C₅H₅)Co{PR₂(O)}₃]^—, R = OMe, OEt The sodium salts of the tripodal oxygen ligands L_R^— = [η⁵‐(C₅H₅)Co{PR₂(O)}₃]^— (R = OMe, OEt) react with the oxovanadium halides V(O)F₃ and V(O)Cl₃ to yield deep red compounds of the type [V(O)X₂L_R]. Halide exchange reactions with [V(O)Cl₂L_OMe] und [V(O)F₂L_OMe] aiming at the preparation of the analogous bromide complex [V(O)Br₂L_OMe] led to the isomer [VO(L_OMe)₂][V(O)Br₄]. The crystal structure of [V(O)Cl₂L_OMe] has been determined by single crystal x‐ray diffraction. The compound crystallizes in the monoclinic space group P2₁/n with a = 9.6332(8), b = 15.0312(11) and c = 15.3742(12)Å, β = 100.181(8)°. The coordination around vanadium is distorted octahedral.     

Decarboxylation syntheses of transition metal organometallics,II.trans-carbonyl(polyhalogenophenyl)bis(triphenylphosphine)rhodium(I) compounds

Summary The rhodium(I) carboxylates,trans-RhO₂CR(CO)(PPh₃)₂ (R = C₆F₅, C₆Cl₅,p-HC₆F₄,m-HC₆F₄,o-HC₆F₄,p-McOC₆F₄, 4,5-H₂C₆F₃, 3,5-H₂C₆F₃, or 2,6-F₂C₆H₃, have been prepared by reaction of RhH(CO)(PPh₃)₃ with the appropriate polyhalogenobenzoic acids in ethanol and/or by reaction oftrans-RhCl(CO)(PPh₃)₂ with the appropriate thallous carboxylates in benzene. Decarboxylations with formation of polyhalogenoarylrhodium(I) compounds,trans-RhR(CO)(PPh₃)₂ (R = C₆F₅, C₆Cl₅,p-HC₆F₄,m-HC₆F₄,p-MeOC₆F₄, 4,5-H₂C₆F₃ or 3,5-H₂C₆F₃), have been achieved either by decomposition of the corresponding rhodium(I) carboxylates in pyridine or by reaction oftrans-RhCl(CO)(PPh₃)₂ and the thallous carboxylates in pyridine, but the derivatives R =o-HC₆F₄ or 2,6-F₂C₆H₃ could not be obtained by this method. The rate of decarboxylation decreased in the sequence R = C₆F₅ >p-MeOC₆F₄ >p-HC₆F₄ >m-HC₆F₄ > 4,5-H₂C₆F₃ > 3,5-H₂C₆F₃.Part 1, ref. 10.Preliminary communication, ref. 9.     

Basicity of bisperhalophenyl aurates toward closed-shell metal ions: metallophilicity and additional interactions

The interaction of bisperhalophenyl aurates [AuR₂]^? (R?=?C₆F₅, C₆F₃Cl₂, and C₆Cl₅) with the closed-shell Ag⁺, Cu⁺, and Tl⁺ ions has been studied theoretically and compared with the experimentally known X-ray diffraction crystal structures. Initially, the aurates have been fully optimized at MP2 level of theory in a D _2h symmetry. The analysis of the basicity of the three aurates [AuR₂]^? (R?=?C₆F₅, C₆F₃Cl₂ and C₆Cl₅) against Ag⁺ ions in a C _2v symmetry has been calculated in point-by-point bsse-corrected interaction energy analysis at HF and MP2 levels of theory. Taking into account the experimental observation of additional interactions between the heterometals and C _ipso atoms at the perhalophenyl rings or halogen atoms at the ortho position of the perhalophenyl rings, dinuclear models of the type [AuR₂]^?···Ag⁺ (R?=?C₆Cl₅, and C₆F₅); [AuR₂]^?···Cu⁺ (R?=?C₆F₅, and C₆Cl₅) and [AuR₂]^?···Tl⁺ (R?=?C₆F₅, and C₆Cl₅) with a C _2v , C ₂ , and C _s symmetries have been optimized at DFT-B3LYP level. The interaction energies have been computed through bsse-corrected single point HF and MP2 calculations. The energy stabilization provided and the heterometal preference have been analyzed and compared with the experimental results.     

Pseudo-spectral dipole oscillator-strength distributions for SO2, CS2 and OCS and values of some related dipole—dipole and triple-dipole dispersion energy constants

Pseudo-spectral dipole oscillator strengths and excitation energies, which are discrete representations of the original continuous dipole oscillator-strength distributions (DOSDs), are presented for the ground-state SO₂, CS₂ and OCS molecules. These pseudo-DOSDs, together with previously published pseudo-DOSDs, are used to evaluate the dipole—dipole and triple-dipole dispersion-energy coefficients for all the two- and three-body interactions between SO₂, CS₂ and OCS and between these molecules and H₂, N₂, O₂, NO, N₂O, H₂O, NH₃, CO, CO₂, CH₄, C₂H₆, C₄H₁₀ and C₆H₁₄, with an estimated uncertainty of 1–2%. The importance of results of this type is discussed briefly.     

Disproportionation reactions between alkyl and fluoroalkyl radicals. V. Perfluoro-n-propyl and ethyl radicals revisited

A redetermination of the disproportionation/combination ratio for n–C₃F₇ and C₂H₅ radicals gives a value of Δ(n–C₃F₇, C₂H₅) = 0.13 ± 0.01, independent of the temperature. The radicals were produced by the photolysis of n–C₃F₇COC₂H₅. The previous determinations of this ratio are discussed and are found to be largely incorrect. The values for Δ(CF₃, C₂H₅) and Δ(C₂F₅, C₂H₅) are also re-evaluated, and the recommended values are 0.10 ± 0.02 and 0.12 ± 0.02, respectively. Systems involving perfluoroalkyl and ethyl radicals are complicated due to rapid perfluororadical addition to the ethylene formed in the disproportionation process. The extent of this reaction, and its consequences, are discussed and evaluated. The role of the propionyl (C₂H₅CO) radical in the room temperature photolysis is also assessed. However, it is found that the Δ values determined by the intercept method used in this work are not affected by the secondary reactions that occur. It is concluded that high cross-combination ratios are general to perfluoroalkyl-alkyl radical interactions. For C₃F₇ and C₂H₅ radicals the ratio is 2.7–2.8. Above 100°C ratios exceed 3 due to secondary reactions.     

Reactions of Dicyclopentadienyltitanium(III) compounds with carbon monoxide

Reactions of Cp₂TiR (R = Cl, C₆F₅, C₆H₅, o-CH₃C₆H₄) with CO give two types of products: terminally coordinated adducts, Cp₂Ti(R)CO, and insertion products, Cp₂TiCOR, i.e. acyl compounds. The acyl ligand is η²-coordinated at the titanium atom. The preparations and properties of the compounds are described.     

New Dinuclear Ru2(CO)4 Sawhorse‐Type Complexes Containing Bridging Carboxylato Ligands

The thermal reaction of Ru₃(CO)₁₂ with ethacrynic acid, 4‐[bis(2‐chlorethyl)amino]benzenebutanoic acid (chlorambucil), or 4‐phenylbutyric acid in refluxing solvents, followed by addition of two‐electron donor ligands (L), gives the diruthenium complexes Ru₂(CO)₄(O₂CR)₂L₂ ( 1 : R = CH₂O‐C₆H₂Cl₂‐COC(CH₂)C₂H₅, L = C₅H₅N; 2 : R = CH₂O‐C₆H₂Cl₂‐COC(CH₂)C₂H₅, L = PPh₃; 3 : R = C₃H₆‐C₆H₄‐N(C₂H₄‐Cl)₂, L = C₅H₅N; 4 : R = C₃H₆‐C₆H₄‐N(C₂H₄‐Cl)₂, L = PPh₃; 5 : R = C₃H₆‐C₆H₅, L = C₅H₅N; 6 : R = C₃H₆‐C₆H₅, L = PPh₃). The single‐crystal structure analyses of 2 , 3 , 5 and 6 reveal a dinuclear Ru₂(CO)₄ sawhorse structure, the diruthenium backbone being bridged by the carboxylato ligands, while the two L ligands occupy the axial positions of the diruthenium unit.