Heterobimetallic Mo---Sn complexes. Reactions of [Mo(CO)3(CH3CN)2(Cl)(SnRCl2)] (R = Me, Ph) with 4(4-XC6H4)3 (X = Cl, F, H, Me, MeO)

Three families of heterobimetallic compounds were obtained by reaction of [Mo(CO)₃(CH₃CN)₂(Cl)(SnRCl₂)] (R = Ph, Me) with P(4-XC₆H₄)₃ (X = Cl, F, H, Me, MeO). The type of compound obtained dependent on the solvent and concentration of the starting compound. So, [Mo(CO)₂(CH₃COCH₃)₂(PPh₃)(Cl)(SnRCl₂)]·nCH₃COCH₃ (R = Ph, n = 0.5; R = Me, n = 1) (type I) and [Mo(CO)₃{P(4-XC₆H₄)₃}(μ-Cl)(SnRCl₂)]₂ (R = Ph, X = Cl, F, H, Me, MeO; R = Me, X = Cl, F) (type II) were isolated from acetone solution in ca 0.05 M and 0.1 M concentrations, respectively. However, [Mo(CO)₃(CH₃CN) {P(4-XC₆H₄)₃}(Cl)(SnRCl₂)] (R = Ph, X = H; R = Me, X = Cl, F, H) (type III) were obtained from dichloromethane solution independently of the concentration used. All new complexes showed a seven-coordinate environment at molybdenum, containing Mo---Cl and Mo---Sn bonds. Mössbauer spectra indicated a four-coordination at tin for type III complexes.     

Synthese und reaktivität von dienylmetall-verbindungen : XXVII. Ein einfacher weg zur synthese von cyclopentadienylcobalt(III)-dikationen

CpCo(CO)₂ is oxidised by [Cp₂Fe]BF₄ (Cp = C₅H₅) in the presence of neutral ligands L to give the dications [CpCoL₃]²⁺ (L = SMe₂, S(n-C₄H₉)₂, PMe₃, C₅H₅N, MeCN; Me = CH₃). In [CpCo(SMe₂)₃]²⁺, sulfane ligands are substituted by neutral ligands L, L---L and L---L---L, to give the complexes [CpCoL₃]²⁺ (L = SeMe₂, TeMe₂, PMe₃, P(OMe)₃, AsMe₃, SbMe₃, t-C₄H₉NC, C₅H₅N, MeCN), [Cp-Co(L---L)SMe₂]²⁺ (L---L = R₂P(CH₂)_nPR₂, n = 1, 2, R = C₆H₅; bipyridine, o-phenanthroline, neocuproin) and [CpCo(L---L---L)]²⁺ (L---L---L = RP(CH₂CH₂PR₂)₂, R = C₆H₅). The dications react with iodide resulting in the monocations [CpCoL₂I]⁺ and [CpCo(L---L)I]⁺. Azacobaltocinium cations [CpCo(C₄R₂H₂N)]⁺ (R = H, CH₃) are obtained by reaction of [CpCo(SMe₂)₃]²⁺ with metal pyrrolides.     

新型双四面体过渡金属簇合物的合成与表征

利用Co₂(CO)₈与[Cl₃CC(O)OCH₂]₂的反应合成了以C(O)OCH₂CH₂OC(O)桥联两个Co₃C四面体骨架为特征的新型双四面体簇合物[(CO)₉Co₃(μ₃-C)C(O)OCH₂]₂(1);1与不同物质的量比的Na[M(CO)₃C₅H₄R](M=Mo,W;R=H,C(O)Me)反应,得到一步交换的产物(CO)₉Co₃(μ₃-C)C(O)OCH₂CH₂OC(O)(μ₃-C)Co₂M(CO)₈(C₅H₄R)[M=Mo,R=H(2);M=Mo,R=C(O)Me(3);M=W,R=H(4);M=W,R=C(O)Me(5)]或两步交换的产物[(C₅H₄R)(CO)₈Co₂M(μ₃-C)C(O)OCH₂]₂[M=Mo,R=H(6);M=Mo,R=C(O)Me(7);M=W,R=H(8);M=W,R=C(O)Me(9)].5或9分别与Na[Mo(CO)₃C₅H₅]以12的物质的量比反应得到含一个手性四面体骨架(CoMoWC)的(C₅H₅)(CO)₈Co₂Mo(μ₃-C)C(O)OCH₂CH₂O·C(O)(μ₃-C)CoMoW(CO)₇(C₅H₄C(O)Me)(C₅H₅)(10)或含两个手性四面体骨架(CoMoWC)的[(C₅H₅)(C₅H₄C(O)Me)(CO)₇CoMoW(μ₃-C)C(O)OCH₂]₂(11);对化合物1_11进行了CH元素分析、IR和¹HNMR等表征.结果表明,在金属交换反应中处于不同簇环境下的Co(CO)₃基团反应活性不同.对化合物1进行了晶体X射线衍射分析.化合物1的晶体属单斜晶系,P2₁/n(#14)空间群,晶胞参数a=0.933 0(2)nm,b=1.519 7(4)nm,c=1.178 3(4)nm,=91.16(2)°,Z=2,F(000)=972.分子结构呈中心对称.     

Synthesis and Characterization of Dinuclear Aluminum Complexes Bearing N,N-Dialkylaniline-amido Ligands and Its Catalytic Properties for Lactone Polymerization

Two ligands [ortho-C6H4NR2（CH2NH）]2CH2CH2（3： R=Me; 4： R=EO were prepared by the reduction of preligands [ortho-C6H4NR2（CH=N）]zCH2CH2（1： R=Me; 2： R=Et）. These ligands reacted with AIMe3 to afford the corresponding dinuclear aluminum complexes {A1Me2[ortho-C6H4NR2（CH2N）]}2CHzCH2（5： R=Me; 6： R=Et）. All the compounds were characterized by 1H and UC nuclear magnetic resonance（NMR） spectroscopies and elemental analyses. The catalytic properties of the aluminum complexes towards the ring-opening polymerization of lactones were investi- gated in the presence of benzvl alcohol. All the oolvmerization reactions were proceeded in a controlled manner.     

Symmetrization of methylmercury(II) and phenylmercury(II) salts induced by the tripodal ligand N(CH2CH2PPh2)3

Both ionic [HgR(DMSO)][CF₃SO₃] (R = Me or Ph) and covalent HgMeI organomercury(II) compounds react with the tripodal ligand N(CH₂CH₂PPh₂)₃ (np₃) to yield as ultimate products Hg(II) complexes, the new five-coordinated [Hg(OSO₂CF₃)(np₃)]⁺ or the known tetrahedral [HgI(np₃)]⁺ and symmetric diorganomercurials respectively. Monitoring of the reactions by ¹H, ³¹P and ¹³C NMR spectroscopy has shown that the mechanistic pathways depend on the nature of the reagents.     

Tricarbonylrhenium(I) complexes of phosphine-derivatized amines, amino acids and a model peptide: structures, solution behavior and cytotoxicity

Modified Mannich reactions of amines, amino acids and a model peptide with Ph₂PH and CH₂O gave bis(diphenylphosphinomethyl)amines (Ph₂PCH₂)₂NR [R=Ph (1), CH₂CH₂OH (2), CH₂COOCH₂Ph (3), CH₂CONHCH₂COOCH₂Ph (4), CH₂COOH (5)] and (Ph₂PCH₂)₂NCH₂CH₂N(CH₂PPh₂)₂ (6). Reaction with [ReBr₃(CO)₃]²⁻ under mild conditions led to [ReBr(CO)₃]{(Ph₂PCH₂)₂NR} [R=Ph (7), CH₂CH₂OH (8), CH₂COOCH₂Ph (9), CH₂CONHCH₂COOCH₂Ph (10), CH₂COOH (11)] and [ReBr(CO)₃(Ph₂PCH₂)₂NCH₂]₂ (12). All new complexes have been characterized by NMR and IR spectroscopy and for 7, 9 and 10, single-crystal X-ray diffraction analyses. Electrospray mass spectrometric studies show that the rhenium–phosphine chelates are very stable, especially in neutral methanolic solution. Hydrolysis of the ester and amide linkages slowly occur in acidic and basic solutions over several weeks; displacement of the bromide ligand also occurs in basic medium. Cytotoxicity testing of 7–10 and 12 showed that all the complexes are active against specific tumor cell lines, especially MCF-7 breast cancer and HeLa-S³ suspended uterine carcinoma.     

Normal coordinate analysis of MSiH3 moieties in transition metal complexes and comparison to results obtained for silyl halides

In order to examine the influence of the transition metal on the metal-silyl fragment MSiH₃ and the metal-silicon bond, polarized Raman spectra of the complexes (C₅R₅)(CO)₂FeSiH₃ R = H (Cp) (1a), Me (Cp^*) (1b)], (C₅H₅)(CO)(PPh₃)FeSiH₃ (1c), (C₅Me₅)(CO)₂RuSiH₃ (2), (C₅R₅)(CO)₂(PMc₃)MoSiH₃ [R = H (3a), Me (3b)], and (C₅R₅)(CO)₂(PMe₃)WSiH₃ [R = H(4a), Me (4b)] have been recorded. The spectral data have been evaluated and interpreted on the basis of a normal coordinate analysis of the MSiH₃ core and the derived force constants and potential energy distributions were compared to results obtained for analogous halogen derivatives in the series XSiH₃ [X = Br (5), I (6)].     

Half-sandwich and mixed-ring uranium complexes

The monocyclooctatetraene uranium complex [U(COT)(I)₂(THF)₂] (COT=η-C₈H₈; THF=tetrahydrofuran), isolated from the reaction of bis(cyclooctatetraene)uranium with iodine, is a precursor for the synthesis of the alkyl derivatives [U(COT)(CH₂Ph)₂i (HMPA) ₂], [U(COT)(CH₂SiMe₃)₂(HMPA)] (HMPA=hexamethyl phosphorous triamide) and [U(COT)CH₂SiMe₃)₃] [Li(THF)₃] and of the mixed-ring compounds [U(COT)(η-C₅R₅)(I)] (R=H or Me). The last were used to prepare the amide and alkyl complexes [U(COT)(η-C₅H₅)(N{SiMe₃}₂)] and [U(COT)(η-C₅Me₅)(CH₂SiMe₃)].     

含功能取代基的C2Mo2簇合物的合成与晶体结构测定

利用苯乙炔或丙炔醇与[Mo(CO)₂(η⁵-C₅H₄R¹)]₂[R¹＝C(O)Me,C(O)OEt,C(O)Ph]的反应合成了6个新的炔烃配位的双钼化合物[Mo(CO)₂(η⁵-C₅H₄R¹)]₂(μ-η²,η²-(CH=CR²)[R¹＝C(O)Me,R²＝Ph,1;R¹＝C(O)OEt,R²＝Ph,2;R¹＝C(O)Ph,R²＝Ph,3;R¹＝C(O)Me,R²＝CH₂OH,4;R¹＝C(O)OEt,R²＝CH₂OH,5;R¹＝C(O)Ph,R²＝CH₂OH,6],并对这些化合物进行了C/H元素分析,IR,¹HNMR等表征.晶体X射线衍射分析结果表明,化合物1属单斜晶系,P2₁(＃4)空间群,晶胞参数a＝0.7671(2)um,b＝0.8365(2)nm,c＝1.8308(3)nm,β＝98.34(1)°,V＝1.1623(5)um³,Z＝2,D_c＝1.772g·cm^-3,F(000)＝616,R＝0.041,R_w＝0.045.     

Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen : XLV. Eigenschaften und Reaktionsverhalten von Hydrogenchalkogenid-Komplexen der Metalle Chrom, Molybdän und Wolfram

Hydrogensulfido and hydrogenselenido complexes of general composition (η⁵-C₅R₅(CO)3M(EH) (R = H, CH₃; M = Cr, Mo, W; E = S, Se) react at the EH functions by deprotonation, bimolecular elimination of H₂E, or by loss of the chalcogen atoms E. Reactions with Lewis-acidic complex cations such as [((η⁵-C₅R₅)(CO)₃M]⁺ (R = H, CH₃; M = Mo, W) are useful for the synthesis of chalcogen bridged compounds (μ-E)[(η⁵-C₅R₅)(CO)₃M]₂. The heterodinuclear chalcogen bridge complexes thus generated form metathesis equilibria with their corresponding homodinuclear systems.     

Synthesis of metallocenes of zirconium, hafnium, manganese, iron, tin, lead and half-sandwich complexes of rhodium and iridium containing the ligands (η-C5R4CR′2PMe2), where R and R′ may be H or Me

The dimethylphosphino substituted cyclopentadienyl precursor compounds [M(C₅Me₄CH₂PMe₂)], where M=Li⁺ (1), Na⁺ (2), or K⁺ (3), and [Li(C₅H₄CR′₂PMe₂)], where R′₂=Me₂ (4), or (CH₂)₅ (5), [HC₅Me₄CH₂PMe₂H]X, where X⁻=Cl⁻ (6) or PF₆⁻ (7) and [HC₅Me₄CH₂PMe₂] (8), are described. They have been used to prepare new metallocene compounds, of which representative examples are [Fe(η-C₅R₄CR′₂PMe₂)₂], where R=Me, R′=H (9); R=H and R′₂=Me₂ (10), or (CH₂)₅ (11), [Fe(η-C₅H₄CMe₂PMe₃)₂]I₂ (12), [Fe{η-C₅Me₄CH₂P(O)Me₂}₂] (13), [Zr(η-C₅R₄CR′₂PMe₂)₂Cl₂], where R=H, R′=Me (14), or R=Me, R′=H (15), [Hf(η-C₅H₄CMe₂PMe₂)₂]Cl₂] (16), [Zr(η-C₅H₄CMe₂PMe₂)₂Me₂] (17), {[Zr(η-C₅Me₄CH₂PMe₂)₂]Cl}{(C₆F₅)₃BClB(C₆F₅)₃} (18), [Zr{(η-C₅Me₄CH₂PMe₂)₂Cl₂}PtI₂] (19), [Mn(η-C₅Me₄CH₂PMe₂)₂] (20), [Mn{(η-C₅Me₄CH₂PMe₂B(C₆F₅)₃}₂] (21), [Pb(η-C₅H₄CMe₂PMe₂)₂] (23), [Sn(η-C₅H₄CMe₂PMe₂)₂] (24), [Pb{η-C₅H₄CMe₂PMe₂B(C₆F₅)₃}₂] (25), [Pb(η-C₅H₄CMe₂PMe₂)₂PtI₂] (26), [Rh(η-C₅Me₄CH₂PMe₂)(C₂H₄)] 29, [M(η,κP-C₅Me₄CH₂PMe₂)I₂], where M=Rh (30), or Ir, (31).     

新型桥联双四面体簇合物的合成与表征

利用(μ₃-CCO₂Et)Co₃(CO)₉与单阴离子试剂[Mo(CO)₃(η⁵-C₅H₄R)]-[R=H,C(O)Me]的反应合成了2个新的含CCo₂Mo骨架的簇合物(μ₃-CCO₂Et)Co₂Mo(CO)₈(η⁵-C₅H₄R)[R=H(1);R=C(O)Me(2)],进而用其与双阴离子试剂{-M(CO)₃[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,W]反应合成了4个双四面体簇合物{(μ₃-CCO₂Et)CoMoM(CO)₇(η⁵-C₅H₄R)[η⁵-C₅H₄C(O)]}₂-1,4-C₆H₄[M=Mo,R=H(3);M=Mo,R=C(O)Me(4);M=W,R=H(5);M=W,R=C(O)Me(6)].这6个化合物的C和H元素分析,IR,¹HNMR等表征都与其结构一致.晶体X射线衍射分析表明,化合物2属单斜晶系,C₂/c空间群,晶胞参数a=1.1264(3)nm,b=1.1879(3)nm,c=3.3565(10)nm,β=93.320(5)°,V=4.484(2)nm₃,Z=8,D_c=1.867g·cm^-3,F(000)=2480,R=0.0369,wR=0.1150.     

Double bond shifts induced by reaction of hex-5-en-2-one with triosmium clusters

Carbon---hydrogen bond cleavage at the terminal 6-position occurs when hex-5-en-2-one (CH₂=CHCH₂CH₂COMe) oxidatively adds to [Os₃(CO)₁₀(MeCN)₂] to give [Os₃H(μ-CH=CHCH₂CH₂COMe)(CO)₁₀], which is completely analogous to the simple vinyl complex [Os₃H(μ-CH=CH₂)(CO)₁₀]. A minor product from the reaction is [Os₃(CH₃CH=CHCH₂COMe)(CO)₁₀], an isomer in which double-bond migration has occurred to give the βγ-unsaturated ketone; stabilisation occurs through chelation and ketone coordination. [Os₃H₂(CO)₁₀] reacts with CH₂=CHCH₂CH₂COMe in refluxing cyclohexane to give a third isomer, [Os₃H(CH₃CH₂C=CHCOMe)(CO)₁₀], in which further double bond migration has occurred to give the β-unsaturated ketone. Metallation at the β-site gives an Os---C bond as part of a 5-membered chelate ring. Thermolysis of each of the three isomeric decarbonyl species in refluxing cyclohexane or heptane leads to the elimination of an Os(CO)₄ group to give the dinuclear compound [Os₂H(EtC=CHCOMe)(CO)₆] in varying yield. Pathways from γδ to the βγ and finally the β unsaturated ketones may be mapped out.     

Acyl complexes of molybdenum: structural and reactivity studies

The following structural peculiarities of the agostic acyl structure ₂R) (R = H, SiMe₃) and some characteristic chemical reactivity of the M-η²-acyl and iminoacyl linkage are described. (i) A structural comparison of the bonding parameters within three agostic acetyl Mo complexes containing the dithioacid ligand, indicates that the agostic interaction strengthens upon increasing the electron-releasing properties of the S-chelating ligand. (ii) The acyl-xanthate complex Mo(C(O)Me)(S₂COR)(CO)(PMe₃)₂ undergoes loss of a sulfur atom from the coordinated xanthate and coupling with the acyl ligand to form complexes containing coordinated alkoxythiocarbonyl and monothioacetate ligands. The latter can be metathetically replaced by KS₂COR. (iii) Upon heating at 70°C η²-acyl-dicarbonyl bispirazolilborate complexes of molybdenum of the type Mo(H₂B(pz^*)₂)(η²-C(O)Me)(CO)₂(PMe₃) (pz^* = 3,5-dimethyl-pyrazol-1-yl) yield functionalized acyl ligands derived from the stereo- and regioselective intramolecular addition of one of the B---H bonds of the H₂B(pz^*)₂ group across the C=O moiety of the η²-acyl group. (iv) The η²-acyl-isocyanide complexes {Mo}(η²-C(O)R)(CNR′) ({Mo} = Mo(H₂B(pz^*)₂)(CO)(PMe₃)) undergo irreversible thermal isomerization to the corresponding η²-iminoacyl-carbonyl derivatives {MO}(η²-C(NR′)R)(CO). This isomerization reaction follows first-order kinetics.     

Synthesis and electrochemical behaviour of the cyanamide-isocyanide complexes of rhenium, trans-[ReL(CNR)(Ph2PCH2CH2PPh2)2] ( L = NCNH2 or NCNH)

Reaction of trans-[ReCl(CNR)(dppe)₂] (R = Me (Ia) or ^tBu (Ib); DPPE = Ph₂PCH₂CH₂PPh₂) in CH₂Cl₂ with cynamide in the presence of TlBF₄ forms the new cynamide-isocyanide complexes trans-[Re(CNR)(NCNH₂)(dppe)₂][BF₄] (R = Me (IIa) or ^tBu (IIb)), which upon treatment by ^tBuOK or Et₃N give trans-[Re(NCNH)(CNR)(dppe)₂] (R = Me (IIIa) or ^tBu (IIIb)). The electrochemical behaviour of these species was studied by cyclic voltammetry and controlled potential electrolysis at a Pt electrode in an aprotic solvent, and cathodic reduction of II results in the formation of III.     

Synthesis and characterization of oxo---imido and alkyl---imido complexes of molybdenum(VI)

Treatment of the complex Mo(Nmes)(O)Cl₂(dme) (mes=2,4,6-trimethylphenyl; dme=1,2-dimethoxyethane) with KTp^Me2, NaCp and bipy gives the corresponding derivatives (Tp^Me2)Mo(Nmes)(O)Cl (1), CpMo(Nmes)(O)Cl (2) and Mo(Nmes)(O)Cl₂(bipy) (3). Other oxo---imido compounds of composition Mo(Nmes)(O)(S₂CNR₂)₂ (R₂=C₄H₄ 4, C₅H₁₀ 5, ⁱPr₂ 6) can be obtained by reacting Mo(Nmes)(O)Cl₂(dme) with the appropriate dithiocarbamate salt. The NMR properties of 4–6 are consistent with the presence of two rapidly equilibrating dithiocarbamate ligands. The reaction of Mo(Nmes)(O)Cl₂(dme) with different Grignard reagents, Mg(R)X, produces the trialkyl imido complexes Mo(Nmes)R₃Cl (R=Me 7, CH₂C(Me)₂Ph 8, CH₂SiMe₃ 9).     

Mehrfachbindungen zwischen Hauptgruppenelementen und Übergangsmetallen : XLIV. Synthesen von Hydrogensulfido- und Hydrogenselenido-Komplexen der Metalle Chrom, Molybdän und Wolfram

Hydrogenchalcogenido complexes of general composition (η⁵-C₅R₅)(CO)₃M(EH) (R = H, CH₃; M = Cr, Mo, W; E = S, Se) can be obtained by three different routes, sometimes in quite good yields. Thus, the sulfur and selenium derivatives can be synthesized by insertion of the respective elements into the metal-hydrogen bonds of the precursor compounds (η⁵-C₅R₅)(CO)₃MH. This species also reacts with potassium selenocyanate to yield the hydrogenselenido derivatives (η⁵-C₅R₅)(CO)₃M(SeH) which can also be obtained by treatment of the methyl complexes (η⁵-C₅R₅)(CO)₃M(CH₃ (M = Mo, W) with HBF₄ and Li[SeH]. The corresponding hydrogentellurido compounds are probably formed by these preparative methods but appear to be quickly converted into either the dinuclear tellurium bridge products (μ-Te)[(η⁵-C₅R₅)(CO)₃M]₂ (M = Mo) or into the hydrido complexes (η⁵-C₅R₅)(CO)₃MH (M= Mo, W) by release of elemental tellurium.     

Group 6 carbene complexes derived from lithiated azoles and the crystal structure of a molybdenum thiazolinylidene complex

Fischer-type (alkoxy)azolyl carbene complexes and Öfele–Lappert-type azolylinylidene complexes were synthesised by reaction of 1-phenylpyrazol-3-yllithium, 4-methylthiazol-2-yllithium, benzothiazol-2-yllithium, 1-methylimidazol-2-yllithium with M(CO)₅L (L=CO, THF or Cl⁻; M=Cr, Mo or W) and subsequent alkylation with CF₃SO₃CH₃. The alkylation of Fischer-type carbene complexes containing an azolyl as the organic substituent proceeded via ring opening of tetrahydrofuran. When the alkylation is carried out in THF, the carbocation CH₃O(CH₂)₄⁺ acts as an electrophile. Protonation rather than alkylation of coordinated imidazolyl furnished cyclic imine complexes. Changing the donor atom of a coordinated thiazole from N to C by deprotonation and alkylation afforded a carbene complex.     

The chemistry of compounds of the type Ru(η---C5Me4Et)(CO)2X (X=Cl, Br or I)

The title compounds react with unidentate ligands, L, containing either phosphorus or arsenic donor atoms to yield the corresponding compounds of the type Ru(η⁵---C₅Me₄Et)(CO)LX; with didentate phosphorus donor ligands the major species formed is the bridged complex {Ru(η⁵---C₅Me₄Et)(CO)X}₂{Ph₂P(CH₂)_nPPh ₂} n = 1, X = Br; n = 2, X = Cl). In contrast, unidentate ligands containing nitrogen donor atoms such as pyridine did not react with Ru(η⁵---C₅Me₄Et)(CO)₂Cl although reaction with 1,10-phenanthroline or diethylenetriamine yielded the ionic products [Ru(η⁵---C₅Me₄Et)(CO)L]⁺Cl⁻ (L = phen or (NH₂CH₂CH₂)₂NH). Reaction of Ru(η⁵---C₅Me₄Et)(CO)₂Br with AgOAc yielded the corresponding acetato complex Ru(η⁵---C₅Me₄Et)(CO)₂0Ac. Ru(η⁵--- C₅Me₄Et)(CO)₂X reacts with AgY (Y = BF₄ or PF₆) in either acetone or dichloromethane to give the useful solvent intermediates [Ru(η⁵---C₅Me₄Et)(CO)₂(solvent)]⁺Y⁻, which readily react with ligands L to yield ionic derivatives of the type [Ru(η⁵---C₅Me₄Et)(CO)₂L]⁺Y⁻ (where L = CO, NCMe, py, C₂H₄ or MeO₂CCCCO₂Me).     

Chromium(III) complexes of polydentate and macrocyclic selenoethers—synthesis, spectroscopic and exafs studies

The reaction of [CrX₃(thf)₃] (X = Cl or Br) with the isometric triselenoethers MeC(CH₂SeMe)₃ and Se(CH₂CH₂CH₂SeMe)₂ (L) forms the very moisture sensitive [CrX₃L] complexes. The macrocycle [16]aneSe₄ (1,5,9,13-tetraselenacyclohexadecane) forms [CrX₂([16]aneSe₄)]PF₆. The complexes have been characterized by analysis, IR and UV-visible spectroscopy and electrospray mass spectrometry. The UV-visible spectra have been analysed and the low 10Dq and large B values, are consistent with weak binding of the soft selenium ligands to the hard Cr^III. Chromium K-edge EXAFS data has been recorded and analysed for the chromium chloride complexes to produce Cr---Se and Cr---Cl distances, which provide further strong evidence for weak Cr^III-selenoether interactions.