Cobalt (iron) thiolato complexes containing the Co-ligand phosphine and reaction products of the structural fragment ML 2 L′ (L = 1,2-bidentate thiolate,L′= tertiary phosphine)

Mono-, di-, tri-, and tetra-nuclear cobalt (iron) complexes containing co-ligands phosphine and thiolate are presented according to the classification by combination of different dentates of the two ligands. Emphasis is being put on the triand tetranuclear cluster complexes of monodentate phosphines and 1,2-bidentate thiolates. These complexes are considered to be constructed based on the general structural fragment (or building block) ML ₂L (L=1,2-bidentate thiolate,L=tertiary phosphine). Structural regularities are presented in Tables I, III, IV, and V and discussed. FAB mass spectroscopic data showed the possible fragmentation patterns. Synergism of the cluster skeletons is proposed to explain the occurrence of the distinct structural modes.Abbreviations Bu _n ³ P tri-n-butylphosphine - dmpe 1,2-bis(dimethylphosphino)ethane - dmpm 1,2-bis(dimethylphosphino)methane - dppe 1,2-bis(diphenylphosphino)ethane - dppep bis(2-diphenylphosphinoethyl)phenylphosphine - dppm 1,1-bis(diphenylphosphino)methane - dppp 1,3-bis(diphenylphosphino)propane - Et₃P triethylphosphine - Ph₃P triphenylphosphine - tepme 1,1,1-tris(diethylphosphinomethyl)ethane - tppme 1,1,1-tris(diphenylphosphinomethyl)ethane - H₂bdt 1,2-benzenedithiol - H₂edt 1,2-ethanedithiol - Hmbt 2-mercaptobenzothiazole - H₂mp 2-mercaptophenol - Hmp 2-hydroxythiophenolate - Hmpo 2-mercaptopyridine-N-oxide - H₂mpp 2-mercapto-3-hydroxypyridine - Hmpp 3-hydroxy-2-pyridinothiolate - H₂pdt 1,2-propanedithiol - HSPh thiophenol - H₂tdt 4-methyl-1,2-benzenedithiol(4-toluenedithiol) - R₂dtc dialkyldithiocarbamate - (RO)₂dtp dialkyldithiophosphate     

Intramolecular CH Activation and Metallacycle Aromaticity in the Photochemistry of [FeFe]‐Hydrogenase Model Compounds in Low‐Temperature Frozen Matrices

The [FeFe]‐hydrogenase model complexes [(μ‐pdt){Fe(CO)₃}₂], [(μ‐edt){Fe(CO)₃}₂], and [(μ‐mdt){Fe(CO)₃}₂], where pdt=1,3‐propanedithiolate, edt=1,2‐ethanedithiolate, and mdt=methanedithiolate, undergo wavelength dependent photodecarbonylation in hydrocarbon matrices at 85 K resulting in multiple decarbonylation isomers. As previously reported in time‐resolved solution photolysis experiments, the major photoproduct is attributed to a basal carbonyl‐loss species. Apical carbonyl‐loss isomers are also generated and may undergo secondary photolysis, resulting in β‐hydride activation of the alkyldithiolate bridge, as well as formation of bridging carbonyl isomers. For [(μ‐bdt){Fe(CO)₃}₂], (bdt=1,2‐benzenedithiolate), apical photodecarbonylation results in generation of a 10 π‐electron aromatic FeS₂C₆H₄ metallacycle that coordinates the remaining iron through an η⁵ mode.     

Planar Ni(II) 1,2-dithiolenes involving bidentate P-donor ligands

A series of planar Ni(II) dithiolenes derived of maleonitriledithiol (mnt), benzene-1,2-dithiol (bdt) and toluene-3,4-dithiol (tdt) with bidentate P,P-ligands (dppe = 1,2-bis(diphenylphosphino)ethane, dppp = 1,3-bis(diphenylphosphino)propane, dppb = 1,4-bis(diphenylphosphino)butane, dpppn = 1,5-bis(diphenylphosphino)pentane) of the [Ni(P,P)(dithiol)] type have been synthesized. The compounds have been characterized by elemental analysis, IR and electronic spectroscopies, magnetochemical, conductivity measurements and thermal analysis. Single crystal X-ray analysis of [Ni(dpppn)(mnt)] confirmed a planar geometry of NiP₂S₂ chromophore. Possible practical applications such as use of these compounds for vulcanization accelerators and their anticholinesterase activity were evaluated.     

Planar Ni(II) 1,2-dithiolenes involving bidentate N -donor ligands

A series of planar Ni(II) dithiolenes derived from maleonitriledithiole (mnt), benzene-1,2-dithiole (bdt) and 1-toluene-3,4-dithiole (tdt) with bidentate N,N-ligands (bpy = 2,2′-bipyridine; phen = 1,10-phenanthroline, nphen = 5-nitro-1,10-phenanthroline) of the [Ni(N,N)(dithiol)] type have been synthesized. The compounds have been characterized by elemental analysis, IR and electronic spectroscopies, magnetochemical and conductivity measurements. Single crystal X-ray analysis of [Ni(phen)(bdt)] confirmed a planar geometry of NiN₂S₂. Possible practical applications such as use for vulcanization catalytic agents and for their anticholinesterase activity were evaluated.     

Complex Equilibria of Organotin(IV) in Aqueous Solution with Imidazole Derivatives

Summary. Equilibria studies in aqueous solution containing 25% dioxane (V/V) are reported for dimethyltin(IV) and trimethyltin(IV) (M) complexes with some imidazole derivatives (L). Stoichiometry and stability constants for the complexes formed were determined at 25°C and ionic strength 0.1M NaNO₃. The results of the dimethyltin(IV) complexes showed the best fit of the titration curves when complexes ML, ML ₂, ML ₂H_–1, and ML ₂H_–2 were expected beside the hydrolysis products of the dimethyltin(IV) cation, while the calculations of the trimethyltin(IV) complexes reported the presence of only the complexes ML, MLH_–1, and the hydrolysis products of the trimethyltin(IV) cation. The concentration distribution of each species of the complexes in solution was evaluated. The stability of all complexes formed was investigated and discussed in terms of molecular structure of the ligand imidazole and the nature of the alkyltin cation. It is deduced that the stability of the complex formed increases as the basicity of the ligand imidazole is increased. On the other hand, the trimethyltin(IV) cation has a very low ability to form complexes compared to the dimethyltin(IV) cation.Received November 22, 2002; accepted (revised) March 3, 2003 Published online August 18, 2003     

Synthesis and structural studies of Co(II) and Ni(II) complexes of glutaric- and adipic dihydrazides

Glutaric dihydrazide (GDH) and adipic dihydrazide (ADH) have been found to react with Co(II) chloride and Ni(II) chloride and nitrate in ethanolic solution to form complexes of the general empirical compositionsMLCl₂,ML ₂Cl₂ and [NiL ₂(H₂O)₂] (NO₃)₂ whereM=Co(II), Ni(II) andL=GDH,ADH. Tetrahedral geometry has been proposed for 11 complexes of Co(II) and octahedral geometry for the remaining complexes based on measurements of molar conductance, magnetic susceptibility, electronic and ir spectra.

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Synthese und Struktur von Co(II)- und Ni(II)-Komplexen von Glutarsäure- und Adipinsäuredihydraziden

Zusammenfassung Glutarsäuredihydrazid (GDH) und Adipinsäuredihydrazid (ADH) bilden mit Co(II)-Chlorid und Ni(II)-Chlorid bzw.-Nitrat in ethanolischer Lösung Komplexe der generellen ZusammensetzungenMLCl₂,ML ₂Cl₂ und [NiL(H₂O)₂] (NO₃)₂, mitM=Co(II), Ni(II) undL=GDH,ADH. Für 11-Komplexe von Co(II) wird eine tetragonale Geometrie, für alle anderen Komplexe eine oktaedrische Geometrie vorgeschlagen. Die Basis dazu lieferten Messungen der molaren Leitfähigkeit, der magnetischen Suszeptibilität und der UV- bzw. IR-Spektren.

     

trans‐Bis­[ethane‐1,2‐di­thiol­ato(2–)‐S,S′]­bis(2‐mer­cap­to­pyri­dine‐S)­tin(IV)

The title compound, [Sn(C₅H₅NS)₂(C₂H₄S₂)₂], was obtained from a 1:2 mixture of bis­(ethane‐1,2‐di­thiol­ato)­tin(IV) and 2‐mercapto­pyridine. The mol­ecules are discrete monomeric trans‐octahedral units, with the Sn^IV atom at the centre of symmetry, planar 2‐mercapto­pyridine zwitterions and SnS₂C₂ groups in twist–envelope conformations. The 2‐mercapto­pyridine ligands are monodentate and are bonded through the S atoms. The S—Sn distances between the S atom of edt (edt is ethane‐1,2‐di­thiol­ate) and the Sn atom are 2.473 (1) and 2.505 (1) Å, which are slightly longer than the S—Sn distance in Sn(edt)₂ of 2.390 (1) Å. The bond between the 2‐mercapto­pyridine S atom and the Sn atom are, remarkably, weaker than the S—Sn bond involving edt.     

Synthesis and characterisation of some complexes of manganese(II) and iron(II) picrates with heterocyclic amines

Summary Complexes of manganese(II) and iron(II) picrates with various bidentate (L) and monodentate (L) heterocyclic bases have been synthesised; their compositions have been established as [ML₃]A₂ (1), [ML₂ · 2 H₂O]A₂ (2), [ML₆]A₂ (3) and [ML4 · 2 H₂O]A₂ (4), where M = Fe^II and Mn^II, L = 2,2-bipyridyl (bipy) and 1,10-phenanthroline (phen) in (1), A = picrate anion; M = Mn^II, L = bipy and phen in (2); M = Fe^II, L = pyridine (py), 4-picoline (4-pic) and 3-picoline (3-pic) in (3); M = Mn^II, L = py, 4-pic, quinoline (quin) and 2,6-lutidine (2,6-lut) in (4) and also M = Fe^II, L = quin and 2,6-lut.     

Rhenium(V) complexes with thiolato and dithiolato ligands: synthesis, structures, and monomerization reactions

The new compound {(PhS)(2)ReO(mu-SPh)}(2), 1, was synthesized from Re(2)O(7) and PhSH and then used as the synthon for a number of hitherto unknown oxorhenium(V) compounds. Reactions between dithiols and 1 (2:1 ratio) afford {PhSReO(dt)}(2), where the dithiols, dtH(2), are 1,2-ethanedithiol (edtH(2)), 1,3-propanedithiol (pdtH(2)), 1,3-butanedithiol (pdtMeH(2)), 1,2-benzenedithiol (bdtH(2)), 2-(mercaptomethyl)thiophenol (mtpH(2)), and 2-mercaptoethyl sulfide (mesH(2)). Similar reactions carried out with a 3:1 ratio of dtH(2) to 1 afford [(ReO)(2)(dt)(3)], dt = edt, pdt. When NEt(3) was introduced prior to the 3:1 reaction between edtH(2) and 1, a compound containing an anionic complex was isolated, [PPh(4)][ReO(edt)(2)]. The new compounds were characterized analytically, spectroscopically, and crystallographically. The Re-O groups in two of the compounds, 1 and {ReO(mu-SPh)(bdt)}(2), exist in rare anti orientations; the others adopt the more familiar syn geometry, as discussed. Selected monomerization reactions of {PhSReO(dt)}(2) were also carried out: {PhSReO(dt)}(2) + 2L = 2[PhSReO(dt)L]. The rate for L = 4-phenylpyridine is given by v = {k(a)[L] + k(b)[L](2)} x [{PhSReO(dt)}(2)], as it is for the reactions of {MeReO(dt)}(2); for all of these compounds, the reaction proceeds nearly entirely by the third-order pathway. Values of k(b)/L(2) mol(-2) s(-1) at 25.0 degrees C are 5.8 x 10(2) (mtp), 2.97 x 10(3) (pdt), 4.62 x 10(5) (edt), and 3.87 x 10(5) (bdt). The rate law for the reactions of {PhSReO(dt)}(2) with L = PAr(3) is v = k(a)[L]/{1 + kappa[L]} x [{PhSReO(dt)}(2)]. For PPh(3), values at 25.0 degrees C of k(a)/L mol(-1) s(-1) (kappa/L mol(-1)) for {PhSReO(dt)}(2) are 9.64 x 10(-2) (1.87) for mtp, 3.43 x 10(-2) (0.492) for pdt, 1.91 (1.42) for edt, 1.84 x 10(-2) (0.82) for bdt, and 1.14 x 10(3) (10.6) for 1. Mechanisms are proposed that are consistent with the data obtained and with earlier work.     

Preparation and structure of cobalt(II), nickel(II), copper(II) and zinc(II) complexes with 3-amino-5-(α/β)pyridyl-1, 2, 4-triazoles

Summary Complexes of bidentate 3-amino-5-()-pyridyl-1,2,4-triazole (L¹) and 3-amino-5-()-pyridyl-1, 2, 4-triazole (L²) of composition [ML¹Cl₂·H₂O], [ML²Cl₂·H₂O], [ML ₃ ^2/1 Cl₂] and [ML ₃ ^2/2 Cl₂] [M=Co^II, Ni^II, Cu^II, M=Zn^II] have been prepared and characterized by elemental analyses, i.r., u.v./visible, e.s.r. spectra, magnetic moments and molar conductances.     

The coordination chemistry ofN,N′-ethylenebis(2-acetylpyridine imine) andN,N′-ethylenebis(2-benzoylpyridine imine); two potentially tetradentate ligands containing four nitrogen atoms

Summary New complexes of the general formulae [ML_A(H₂O)₂]-Cl₂ (M=Ni or Cu), [ML_AX₂] (M=Co or Cu; X=Cl or Br), [NiL_ABr₂]·H₂O, [ML_A] [MCl₄] (M=Pd or Pt), [NiL_B(H₂O)₂]Cl₂·2H₂O, [ML_BCl₂] (M=Co, Ni, Cu, Pd or Pt; X=Cl or Br) and [ML_B] [MCl₄] (M=Pd or Pt), where L_A=N,N-ethylenebis(2-acetylpyridine imine) and L_B=N, N-ethylenebis(2-benzoylpyridine imine), have been isolated. The complexes were characterized by elemental analyses, conductivity measurements, t.g./d.t.g. methods, magnetic susceptibilities and spectroscopic (i.r., far-i.r., ligand field,¹Hn.m.r.) studies. Monomeric pseudo-octahedral stereochemistries for the Co^II, Ni^II and Cu^II complexes andcis square planar structures for the compounds [ML_BX₂] (M=Pd or Pt; X=Cl or Br) are assigned in the solid state. The molecules L_A and L_B behave as tetradentate chelate ligands in the Co^II, Ni^II, Cu^II and Magnus-type Pd^II and Pt^II complexes, bonding through both the pyridine and methine nitrogen atoms. A bidentateN-methine coordination of the Schiff base L_B is assigned in the [ML_BX₂] complexes (M=Pd or Pt; X=Cl or Br). The anomalous magnetic moment values of the Co^II complexes are discussed.     

Synthesis and intramolecular cyclization of 2‐methylsulfany‐4‐oxo‐3(4H)‐quinazolinyl)acetohydrazide

Treatment of ambident sodium salt of 2‐methylsulfanyl‐4(3H)‐quinazolinone with methyl bromoacetate resulted in N₍₃₎‐alkyl ester formation. Reaction of the resulted ester with hydrazine hydrate gave 2‐methylsulfanyl‐4‐oxo‐3(4H)‐quinazolinyl)acetohydrazide, which underwent intramolecular cyclization under heating in dimethylformamide to give 1‐aminoimidazo[2,1‐b]quinazoline‐2,5(1H,3H)‐dione. The latter took place in acylation reaction and in condensation with aromatic aldehydes.     

Cycloaminomethylation of dihydric phenols catalyzed by <Emphasis Type="Italic">d</Emphasis>- and <Emphasis Type="Italic">f</Emphasis>-metal compounds

An efficient method has been developed for the synthesis of 7,16,25-triaryl-7,8,16,17,25,26-hexahydro-6H,15H,24H-tribenzo[f,m,t][1,5,8,12,15,19,3,10,17]hexaoxatriazacyclohenicosines, 3,8-diaryl-2,3,4,7,8,9-hexahydrobenzo[1,2-e:4,3-e′]bis[1,3]oxazines, 3,9-bis(chlorophenyl)-3,4,9,10-tetrahydro-2H,8H-benzo[1,2-e:3,4-e′]bis[1,3]oxazines, and 2,9-bis(chlorophenyl)-1,2,3,8,9,10-hexahydrobenzo[1,2-e:6,5-e′]bis-[1,3]oxazines via cycloaminomethylation of pyrocatechol, resorcinol, and hydroquinone with N,N-bis(methoxymethyl) anilines in the presence of samarium catalysts.     

Zur Kenntnis von Cr2H2(As2O7)(As4O12)

The crystal structure of Cr₂H₂(As₂O₇)(As₄O₁₂) has been determined by X-ray methods using single crystal diffractometer data (1,152 reflections,R=0.054, orthorhombic,Pmmn,a=1317.7 (7),b=1124.9 (6),c=494.3 (4) pm,Z=2). The crystal structure contains both diarsenate(V) and the hitherto unknown cyclo-tetraarsenate(V)-anions. The magnetic susceptibility follows theCurie-Weiss law (=3.86±0.01 _B/Cr³⁺, =–31 K).

     

One Dimensional Face-to-Face Stacking of Anderson–Evans [Cr(OH)6Mo6O18]3− Polyoxometalate Anion: Synthesis, Structure, and Physical Properties of (BEDT-TTF)4[Cr(OH)6Mo6O18]⋅2H2O

The synthesis, structural and magnetic characterizations of a new charge transfer salt (BEDT-TTF)₄[Cr(OH)₆Mo₆O₁₈]2H₂O based on the planar paramagnetic Anderson–Evans polyoxometalate are reported. Structural parameters: T=293 K, triclinic (P ), a=5.9545(2) Å, b=16.3767(6) Å, c=21.8643(6) Å, =110.829(2)°, =91.262(2)°, =98.129(1)°, Z=1, R=0.0540. The crystal structure is characterized by a face-to-face stacking of the anions giving rise to a one-dimensional inorganic chain which develops along the a direction. The organic layers contain two crystallographically independent BEDT-TTF dimers that form alternating stacks along the b direction. This organic chain is perpendicular to the inorganic chains. The charges on BEDT-TTF dimers are deduced to +1.2(1) and +1.7(1) on the basis of the intramolecular bond lengths. The EPR spectrum at 2.5 K is characterized by the superposition of BEDT-TTF⁺ and [Cr^III(OH)₆Mo₆O₁₈]^3– signals. The static susceptibility can be fitted by the Curie–Weiss law down to 1.9 K and the magnetic moment at 300 K is estimated to 4.21 _B , suggesting the uncorrelated spin system with BEDT-TTF⁺ (S=1/2) and Cr^III (S=3/2) ions. This interpretion is consistent with the charge disproportionation on BEDT-TTF dimers along the stack, which is supported by the refined molecular structure and is closely related to the insulating behavior (<10^–9Scm^–1 at RT).     

Metallation studies of organofunctional trisiloxanes

Summary The organofunctional trisiloxanes Me₃SiOSiMe(R)OSiMe₃ [R=(CH₂)₂PPh₂, (CH₂)₃C₅H₄N, (CH₂)₃CN, (CH₂)₂Ph, (CH₂)₂SPh, CH=CH₂ and CH₂CH=CH₂] have been reacted with metal halide and-carbonyl moieties in order to determine the coordination preferences of materials being used as models for metallated longchain linear functionalised polysiloxanes. The products [Me₃SiOSiMe(R)OSiMe₃]₃ML_n [R=(CH₂)₂PPh₂, ML_n=RhCl],cis-[Me₃SiOSiMe(R)OSiMe₃]₂ML_n [R=(CH₂)₂PPh₂ or (CH₂)₃C₅H₄N, ML_n=Mo(CO)₄],trans-[Me₃SiOSiMe(R)OSiMe₃]₂ML_n[R=(CH₂)₂PPh₂, ML_n=NiCl₂, PdCl₂, PtCl₂ and [Rh(CO)Cl] and [Me₃SiOSiMe(R)OSiMe₃]ML_n [R=(CH₂)₂PPh₂, ML_n=Mo(CO)₃(2,2-bipyridine); R=(CH₂)₂Ph, ML_n=Mo(CO)₃; R=(CH₂)₃C₅H₄N, (CH₂)₃CN, or (CH₂)₂SPh, ML_n=Rh(CO)₂Cl; R=CH=CH₂ or CH₂CH=CH₂, ML_n=Fe(CO)₄] have been isolated and characterised spectroscopically in the course of these studies.     

Synthesis and reactions of heterodinuclear organopalladium complex having an unsymmetrical PN ligand

Novel heterodinuclear organopalladium complexes having an unsymmetrical PN ligand (Et₂NC₂H₄PPh₂-κ²N,P)RPd-ML_n (ML_n = Co(CO)₄; R = Me (2a), Ph (2b), ML_n = MoCp(CO)₃; R = Ph (3b)) are synthesized by metathetical reactions of PdRX(Et₂NC₂H₄PPh₂-κ²N,P) (X = I, NO₃) with Na⁺[ML_n]⁻. Reversible dissociation of the Pd-N bond in 3b is revealed by variable temperature NMR studies. Reactions of 2a and 2b with CO yield corresponding acyl complexes (Et₂NC₂H₄PPh₂-κ²N,P)(RCO)Pd-Co(CO)₄ (R = Me (5a), Ph (5b)). Rate of CO insertion for 2a and 2b is significantly faster than those for mononuclear methylpalladium complex, PdMeI(Et₂NC₂H₄PPh₂-κ²N,P) (1a), and methylpalladium-cobalt complex with a 1,2-bis(diphenylphosphino)ethane (dppe) ligand, (dppe-κ²P,P′)MePd-Co(CO)₄ (6a). 5a smoothly reacts with nucleophiles such as diethylamine, methanol and benzenethiol to give corresponding amide, ester and thioester, respectively. These reactions of 5a are also significantly faster than those of corresponding mononuclear analogues and the similar heterodinuclear complexes with symmetrical bidentate ligands such as 1,2-bis(diphenylphosphino)ethane or N,N,N′,N′-tetramethylethylenediamine ligand.     

Manganese(II) complexes with edta-type ligands. The molecular structure of aquo-dihydrogen(1,2-propanediamine-N,N,N′,N′-tetraacetate)manganese(II) trihydrate, [Mn(H21,2-pdta)(H2O)] · 3H2O

New manganese(II) complexes with ethylenediamine-N,N,N,N-tetra-3-propionate (edtp) and 1,2-propanediamine-N,N,N,N-tetraacetate (1,2-pdta) were prepared and characterized by elemental analysis, i.r. spectroscopy and magnetic measurements. The structure of [Mn(H₂1,2-pdta)(H₂O] · 3H₂O was determined by the single crystal X-ray diffraction technique. The complex crystallizes in the space group P2₁/n(#14) of the monoclinic crystal system with unit cell parameters a = 10.993(2) Å, b = 14.092(2) Å, c = 11.753(1) Å, = 96.302(9)⁰, V = 1809.7(3) ų, Z = 4 and R = 0.051. The complex contains seven-coordinated Mn^II ion with H₂1,2-pdta ion acting as hexadentate ligand and one water molecule.     

Substituted metal carbonyls. Part 25: Unidentate,intramolecular, and intermolecular bridging modes of 1,1′-bis(diphenylphosphino)ferrocene inM 3S2(CO)9 (M = Fe,Ru) cluster derivatives

Carbonyl exchange of Fe₃(₃-S)₂(CO)₉ wioth1,1-bis(diphenylphosphino)ferrocene (dppf) in refluxing THF gives a cluster ligand with a pendant phosphine moiety, Fe₃(₃-S)₂(CO)₈ (gn¹-Ph₂PlC₅H₄)Fe(C₅H₄)P⁴ MePh₂)]1 ^–,4. Addition of 1 to AuCl(SMe₂) gives ClAu(-dppf) Fe₄(₃-S)₂(CO)₈,8 (45%). Spectroscopic evidence is also obtained for (OC)₈ (₃-S)₂Fe₃(-dppf) Os₃(CO)₁₁,7 and PdCl₂[(-dppf)Fe₃(₃-D)₂(CO)₈]₂,9, from1 and Os₃(CO)₁₁(CH₃CN) and PdCl₂CN)₂, respectively. Crystal data dor3: space group P2₁/n,a = 10.891(3) Å,b = 19.939(3) Å,c = 20.443(2) Å, 100.17(2)°.Z = 4, 3917 reflections,R = 0.049.