Darstellung von Tetracarbonyl-triphenylphosphinmanganorganoplumbanen R4−nPb[Mn(CO)4P(C6H5)3]n (RCH3, C6H5; n = 1,2)

Preparation of R_4?nPb[Mn(CO)₄P(C₆H₅)₃]_n Compounds (R?CH₃, C₆H₅; n = 1, 2) As the first examples of organolead manganese carbonyls substituted in the manganese carbonyl ligand compounds of the type R_4?nPb[Mn(CO)₄P(C₆H₅)₃]_n (R?CH₃, C₆H₅; n = 1, 2) have been prepared by the alkali salt method from R_4?nPbCl_n and NaMn(CO)₄P(C₆H₅)₃. (C₆H₅)₂Sn[Mn(CO)₄P(C₆H₅)₃]₂ has been gained by the same method and also by thermal ligand exchange. According the IR data the ligand P(C₆H₅)₃ is trans to the tetrahedrally surrounded lead. In solution to compounds are monomeric.     

Darstellung von Acetatoblei(IV)- und Acetatozinn(IV)- manganpentacarbonylen durch Acidolyse von (C6H5)4–n−M[Mn(CO)5]n (M  Sn,Pb; n = 1, 2) mit Essigsäure

Preparation of Acetatolead(1V) and Acetatotin(1V) Manganese Pentacarbonyls by Acidolysis of (C₆H₅)_4?n M[Mn(CO)₅]_n (M ? Sn, Pb; n = 1, 2) with Acetic Acid By acidolysis of (C₆H₅)_4?nM[Mn(CO)₅]_n (M ? Sn, Pb; n = 1, 2) with acetic acid no M? Mn bonds are broken, but M? C bonds. In this reaction (CH₃COO)₂M[Mn(CO)₅]₂ is formed from (C₆H₅)₂M[Mn(CO)₅]₂, and (CH₃COO)₃SnMn(CO)₅ and (CH₃COO)₂C₆H₅PbMn(CO)₅ from (C₆H₅)₃MMn-(CO)₅. (CH₃COO)₂C₆H₅SnMn(CO)₅ is prepared from Cl₂C₆H₅SnMn(CO)₅ and AgCH₃COO. According to IR spectroscopic data the acetato ligands of the diacetato complexes are bidentate, while in (CH₃COO)₃SnMn(CO)₅ bi- and monodentate carboxylate groups are present. For the central atoms Sn and Pb octahedral coordination is proposed.     

Alkyl- und arylverbindungen des vaska'schen typs : IV. cis,trans-Isomerie von iridium-komplexen mit 2,6-dialkylsubstituierten arylliganden

ortho-Substituted aryliridium(I) complexes of the type [Ir(R_nC₆H_5-n)(CO)L₂] (R_nC₆H_5-n = 2-EtC₆H₄; 2,6-Et₂C₆H₃; L = PPh₃ PMePh₂) have been prepared from [IrCl(CO)L₂] and the corresponding aryllithiums. With the exception of trans-[Ir(2-EtC₆H₄)(CO)(PPh₃)₂] these compounds show cis, trans isomerism. After separation, the isomers have been studied by NMR (¹H, ³¹P), IR, and UV-VIS spectroscopy. ab]Durch Umsetzung von [IrCl(CO)L₂] (L = PPh₃, PMePh₂) mit den entsprechenden Lithiumarylen wurden ortho-substituierte Aryliridium(I)-Komplexe des Typs [Ir(R_n C₆H_5-n)(CO)L₂] (R_nC₆H_5?n = 2-EtC₆H₄; 2,6-Et₂C₆H₃; 2-Et-6-MeC₆H₃) dargestellt. Mit Ausnahme von trans-[Ir(2-EtC₆H₄)(CO)(PPh₃)₂] zeigen diese Verbindungen die Erscheinung der cis,trans-Isomerie. Die Isomere wurden getrennt und mit Hilfe NMR- (¹H, ³¹P), IR- und UV/VIS-spektroskopischer Methoden untersucht.     

Kinetic studies in mass spectrometry–VII: Competing cleavage and rearrangement processes in molecular ion decomposition reactions

Apparently competing cleavage and rearrangement reactions in a series of molecular ions have been studied by ionization and appearance potential methods, and by determination of the electron energy dependence of both normal and metastable daughter ion peak intensities. The processes investigated were (i) [M ? CH₃] vs. [M ? CH₂O] in anisole; (ii) [M ? OC₆H₅] vs. [M ? CO] in phenyl ether; (iii) [M ? NO₂] vs. [M ? NO] in nitrobenzene; (iv) [M ? C₃H₇] vs. [M ? C₂H₄] in butyrophenone: (v) [M ? C₃H₇] vs. [M ? C₃H₆] in n-butylbenzene; (vi) [M ? CH₂OH] vs. [M ? CH₂O] in 2-phenylethanol; (vii) [M ? CH₃CO₂] vs. [M ? CH₂CO] in benzyl acetate; and (viii) [M ? C₄H₉O] vs. [M ? C₄H₇] in n-butylbenzoate. The results are interpreted in terms of k vs. E curves with very different frequency factors for the two reaction types. Appearance potentials of metastable ions for the rearrangement reactions have also been measured.     

Alkylidenverbrückte diphosphane und dichlalkogenodiphosphorane als liganden in kationischen cyclopentadienyleisencarbonyl-komplexen

Oxidative cleavage of the FeFe bond in [C₅H₅Fe(CO)₂]₂ in the presence of alkylide-bridged diphosphanes LL (LL = (C₆H₅)₂P(CH₂)_n(P(C₆H₅)₂; n = 1–3), (C₆H₅)₂PCH₂As(C₆H₅)₂ and dichalcogenodiphosphoranes (X)LL(X) ((X)LL(X) = (C₆H₅)₂P(X)(CH₂)_n(X)P(C₆H₅)₂; X  O, S, Se; n = 1–3) yields the complexes [C₅H₅Fe(CO)₂L′]BF₄ (L′ = LL, (X)LL(X); X  S, Se) in high yield. the complexes react with Ni(CO)₄ under photochemical conditions to form [C₅H₅Fe(CO)₂(μ-L′)Ni(CO)₃]BF₄ in quantitative yield, and lose a CO group under irradiation (λ_max > 300 nm) to form the chelate compounds [C₅H₅Fe(CO)L′]BF₄, which are isolable for L′  LL (P,As ligand) and (X)LL(X) (X = S, Se). Some substitution reactions with phosphanes are described.     

Direktsynthese von orthometallierten Ketonen des Typs RCO (o-C6H4)Mn(CO)4−nLn (R = Alkyl- und Arylrest,n = 0, 1, 2, L = Ligand)

Direct Synthesis of Orthometallated Ketones of the Type RCO(o-C₆H₄)Mn(CO)_4?nL_n (R = Alkyl and Aryl Groups, n = 0, 1, 2, L = Ligand) The starting materials of the type RMn(CO)_5?nL_n und (C₆H₅)₂ Hg react to the products of the type RCO(o-C₆H₄)Mn(CO)_4?nL_n[n = 0, R = Ch₃, C₂H₅, C₃H₇, C₆H₅,CH₂; R = C₆H₅, n = 1, L = E(C₆H₅)₃, E = P, As, Sb; R = C₆H₅, n = 2, L = P(OR′)₃, R′ = C₆H₅, CH₃, C₂H₅, C₃H₇]. Steps of their complex reaction pathway are proposed. These orthometallated substances have been characterized by means of ¹H-n.m.r., i.r. and u.v. spectroscopic measurements. The determination of the molecular structure of the two compounds RCO(o-C₆H₄)Mn(CO)₃L [R = C₂H₅, L = CO; R = C₆H₅, L = As(C₆H₅)₃] show that both contain a planar heterocyclic five-membered ring of the type .     

Cyclopentadienyleisen-komplexe mit P(OR)3-liganden; Synthese und spektroskopische charakterisierung

Reactions of reactive cyclopentadienyliron complexes C₅H₅Fe(CO)₂I, [C₅H₅Fe(CO)₂THF]BF₄, [C₅H₅Fe(CO)((CH₃)₂S)₂]BF₄ and [C₅H₅Fe(p-(CH₃)₂C₆H₄)]PF₆ with P(OR)₃ as ligands (R = CH₃, C₂H₅, i-C₃H₇ and C₆H₅) lead to the formation of the complex compounds C₅H₅Fe(CO)_2?n(P(OR)₃)_nI and [C₅H₅Fe(CO)_3?n(P(OR)₃)_n]X (n = 1, 2 and n = 1–3, X = BF₄, PF₆). Spectroscopic investigations (IR, ¹H, ¹³C and ³¹P NMR) indicate an increase of electron density on the central metal with increasing substitution of CO groups by P(OR)₃ ligands. The stability of the compounds increase in the same way.     

Synthese und reaktivität von dienylmetall-verbindungen XXVIII. Über kationen des typs [C5H5Fe(CO)L(EME2)]+ (E = S,Se, Te)

The chiral cations, [CpFe(CO)(EMe₂)L]⁺, are obtained both by reaction of [CpFe(CO)(EMe₂)₂]⁺ with the ligands (L) by heating, and by irradiation of the cations [C₅H₅Fe(CO)₂EMe₂]⁺ in the presence of L (E = S, Se, Te; L = PR₃, AsR₃, SbR₃). The inversion about the chalcogen atom is investigated by DNMR spectrocopy. Compounds of the type [C₅H₅Fe(TeMe₂)L₂]⁺] are formed by irradiation of [C₅H₅Fe(CO)₂(TeMe₂)]⁺ and the ligands (L₂ = 2 PR₃, R = CH₃, OCH₃, OC₆H₅; L₂ = R₂P(CH₂)_nPR₂, R = C₆H₅, n = 1,2,3). ⁷⁷Se and ¹²⁵Te NMR data vary according to the donor properties of the ligand L in the complexes.     

Metallabis(phosphonate) als Chelatliganden. I. Synthese einkerniger Nickelbis(phosphonat)–Komplexe mit OHO-Wasserstoffbrücke und entsprechender Alkali-metall-, Ammonium- und Thallium-Verbindungen

Nickelocen reagiert mit Dialkylphosphiten HP(O)(OR)₂ zu den Komplexen C₅H₅Ni[{P(OR)₂O}₂H] ( 1 :R ? Me; 2 :R ? Et), in denen ein sechsgliedriger NiP₂O₂H-Ring mit einer vermutlich symmetrischen OHO-Wasserstoffbrücke vorliegt. Die Umsetzung von 1 mit HBF₄ führt zu C₅H₅Ni[{P(OMe)₂O}₂BF₂] ( 3 ). Mit NH₃ und Thalliumacetylacetonat entstehen aus 1 bzw. 2 die Komplexe [C₅H₅Ni{P(OR)₂O}₂]NH₄ ( 4, 5 ) und [C₅H₅Ni{P(OR)₂O}₂]Tl ( 6, 7 ). Die entsprechenden Alkalimetallverbindungen [C₅H₅Ni{P(OMe)₂O}₂]M ( 8 :M ? Li; 9 :M ? Na) sind ausgehend von C₅H₅Ni[P(OMe)₃][P(O)(OMe)₂] und LiI bzw. NaI zugänglich. C₅H₅Ni[P(OMe)₃][P(O)(OMe)₂] reagiert mit HgI₂ zu C₅H₅Ni[P(OMe)₃]I und [IHg{P(O)(OMe)₂}]₂. Metallabisphosphonates as Chelating Ligands. I. Synthesis of Mononuclear Nickelbisphosphonates Containing a OHO-Hydrogen Bridge and of Corresponding Alkali Metal, Ammonium, and Thallium Compounds Nickelocene reacts with dialkylphosphites HP(O)(OR)₂ to form the complexes C₅H₅Ni[{P(OR)₂O}₂H] ( 1 :R ? Me; 2 :Et) which contain a six-membered NiP₂O₂H ring with a presumably symmetrically OHO-hydrogen bond. The reaction of 1 with HBF₄ leads to C₅H₅Ni?[{P(OMe)₂O}₂BF₂] ( 3 ). The complexes 1 and 2 react with NH₃ and thallium acetylacetonate to give [C₅H₅Ni{P(OR)₂O}₂]NH₄ ( 4, 5 ) and [C₅H₅Ni{P(OR)₂O}₂]Tl ( 6, 7 ), respectively. The corresponding alkali metal compounds [C₅H₅Ni{P(OMe)₂O}₂]M ( 8 :M ? Li; 9 :M ? Na) are formed in the reaction of C₅H₅Ni[P(OMe)₃][P(O)(OMe)₂] with LiI or NaI. With HgI₂, C₅H₅Ni[P(OMe)₃][P(O)(OMe)₂] reacts to yield C₅H₅Ni[P(OMe)₃]I and [IHg{P(O)(OMe)₂}]₂.     

Heteronukleare Metallatomcluster der Typen X4−n[SnM(CO)4P(C6H5)3]n und M2(CO)8 [μ-Sn(X)M (CO)4P(C6H5)3]2 aus Umsetzungen von SnX2 mit M2(CO)8[P(C6H5)3]2 (X = Halogen; M = Mn,Re; n = 2, 3)

Heteronuclear Metal Atom Clusters of the Types X_4?n[SnM(CO)₄P(C₆H₅)₃]_n and M₂(CO)₈[μ-Sn(X)M(CO)₄P(C₆H₅)₃]₂ by Reaction of SnX₂ with M₂(CO)₈[P(C₆H₅)₃]₂ (X = Halogene; M = Mn, Re; n = 2, 3) The compounds of the both types X_4?n[SnM(CO)₄P(C₆H₅)₃]_n (n = 3; M = Mn; X = F, Cl, Br, I. n = 2: M = Mn, Re; X = Cl, Br, I) and M₂(CO)₈[μ-Sn(X)M(CO)₄P(C₆H₅)₃]₂ (M = Mn; X = Cl, I. M = Re; X = Cl, Br, I) are prepared by reaction of SnX₂ with M₂(CO)₈[P(C₆H₅)₃]₂ (M = Mn, Re). Their IR frequencies are assigned. In Re₂(CO)₈[μ-Sn(Cl)Re(CO)₄P(C₆H₅)₃]₂ the central molecule fragment contains a planar Re₂Sn₂ rhombus with a transannular Re? Re bond of 316.0(2) pm. Each of the Sn^IV atoms is connected with the terminal ligands Cl and Re(CO)₄P(C₆H₅)₃. These ligands are in transposition with respect to the Re₂Sn₂ ring. The mean values for the remaining bond distances (pm) are: Sn? Re = 274.0(3); Sn? Cl = 243(1), Re? C = 176(5), Re? P = 242.4(9), C? O = 123(5). The factors with an influence on the geometrical shape of such M₂Sn₂ rings (M = transition metal) are discussed.     

Thermal studies of some biologically active oxovanadium(IV) complexes containing 8-hydroxyquinolinate and hydroxamate ligands

The thermal decomposition behaviours of oxovanadium(IV)hydroxamate complexes of composition [VO(Q)_2?n(HL^1,2)_n]: [VO(C₉H₆ON)(C₆H₄(OH)(CO)NHO)] (I), [VO(C₆H₄(OH)(CO)NHO)₂] (II), [VO(C₉H₆ON)(C₆H₄(OH)(5-Cl)(CO)NHO)] (III), and [VO(C₆H₄(OH)(5-Cl)(CO)NHO)₂] (IV) (where Q?=?C₉H₆NO^? 8-hydroxyquinolinate ion; HL¹?=?[C₆H₄(OH)CONHO]^? salicylhydroxamate ion; HL²?=?[C₆H₃(OH)(5-Cl)CONHO]^? 5-chlorosalicylhydroxamate ion; n?=?1 and 2), which are synthesised by the reactions of [VO(Q)₂] with predetermined molar ratios of potassium salicylhydroxamate and potassium 5-chlorosalicylhydroxamate in THF?+?MeOH solvent medium, have been studied by TG and DTA techniques. Thermograms indicate that complexes (I) and (III) undergo single-step decomposition, while complexes (II) and (IV) decompose in two steps to yield VO(HL^1,2) as the likely intermediate and VO₂ as the ultimate product of decomposition. The formation of VO₂ has been authenticated by IR and XRD studies. From the initial decomposition temperatures, the order of thermal stabilities for the complexes has been inferred as III?>?I > II?>?IV.     

The sphericity of the diverse 10-vertex polyhedra found in bare post-transition metal clusters: germanium clusters with interstitial magnesium atoms as model systems

Theoretical studies show that pendant dimethylamino groups can play a significant role in the chemistry of unsaturated binuclear dimethylaminoborole iron carbonyls. For [C₄H₄BN(CH₃)₂]₂Fe₂(CO)₅, the lowest energy structures have single CO bridges and Fe?CFe single bonds of lengths ~2.8 ?. The lowest energy [C₄H₄BN(CH₃)₂]₂Fe₂(CO) _n (n?=?4, 3) structures have two bridging CO groups with Fe=Fe double bonds of lengths ~2.5 ? for n?=?4 and three bridging CO groups with Fe??Fe triple bonds of lengths ~2.2 ? for n?=?3. These structures are similar to structures previously found for the corresponding methylborole derivatives (C₄H₄BCH₃)Fe₂(CO) _n . However, slightly higher energy [C₄H₄BN(CH₃)₂]₂Fe₂(CO) _n (n?=?4, 3) structures are found in which dimethylaminoborole is a six-electron donor bridging ligand using electron pairs from the nitrogen atom as well as from the two C=C double bonds. For the more highly unsaturated [C₄H₄BN(CH₃)₂]₂Fe₂(CO) _n (n?=?2, 1), low energy singlet (n?=?2) and triplet (n?=?1) perpendicular structures are also found with similar bridging six-electron donor dimethylaminoborole ligands. In addition, highly unsaturated [C₄H₄BN(CH₃)₂]₂Fe₂(CO) _n (n?=?3, 2, 1) structures are found with agostic hydrogen atoms bridging an iron?Ccarbon bond.     

Reaktionen der Cycloheptatrienylkomplexe [η7-C7H7W(CO)3]BF4 und η7-C7H7Mo(CO)2 Br mit Neutralliganden und die elektrochemische Reduktion des Wolframkomplexes

Reactions of the Cycloheptatrienyl Complexes [η⁷-C₇H₇W(CO)₃]BF₄ and η⁷-C₇H₇Mo(CO)₂Br with Neutral Ligands and the Electrochemical Reduction of the Wolfram Complex Compounds of the type [η⁷-C₇H₇M(CO)₂L][BF₄] (L = P(C₆H₅)₃, As(C₆H₅)₃, Sb(C₆H₅)₃ for M = W and L = N₂H₄ for M = Mo) were synthesized and characterisized. The iodide η⁷-C₇H₇W(CO)₂I reacts with the diphosphine ((C₆H₅)₂PCH₂)₂ to give the trihapto complex η³-C₇H₇ W(CO)₂I((C₆H₅)₂PCH₂)₂. In the case of η⁷-C₇H₇Mo(CO)₂ Br reaction with hydrazine leads to the substitution product [η⁷-C₇H₇ Mo(CO)₂N₂H₄]^⊕, which can be stabilized by large anions. The binuclear complex [C₇H₇W(CO)₃]₂ has been synthesized electrochemically.     

Mass spectra of organometallic compounds—IX: Compounds with metal-metal bonds

The mass spectra of the following compounds have been investigated: (i) The organotin derivatives (CH₃)₃SnMo(CO)₃C₅H₅ and (CH₃)₃SnNCW(CO)₅; (ii) The mercury derivatives Hg[Mn(CO)₅]₂, Hg[Co(CO)₄]₂, Hg[Mo(CO)₃C₅H₅]₂ and ClHgMo(CO)₃C₅H₅; (iii) The polynuclear cyclopentadienyl metal derivatives [C₅H₅Ru(CO)₂]₂, [C₅H₅Cr(CO)₃]₂, [C₅H₅Cr(NO)₂]₂ and [C₅H₅Fe-CO]₄; (iv) The trinuclear cobalt carbonyl derivatives YCCo₃(CO)₉ (Y = Cl and CH₃); (v) The binuclear triene-iron carbonyl derivatives C₄H₄Fe₂(CO)₆ and C₈H₁₀Fe₂(CO)₆. The mass spectra of the trimethyltin derivatives exhibited stepwise loss of methyl groups as well as of carbonyl groups. The mass spectra of the mercury derivatives exhibited the facile loss of mercury. The mass spectrum of [C₅H₅Cr(CO)₃]₂ indicated a very weak chromium-chromium bond since it exhibited no ion containing two chromium atoms. The mass spectrum of the nitrosyl derivative [C₅H₅Cr(NO)₂]₂ exhibited the stepwise loss of its four nitrosyl groups. The mass spectrum of [C₅H₅FeCO]₄ was rather complex and exhibited a variety of unusual processes including eliminations of neutral Fe and C₅H₅Fe fragments. Unusual ions observed in the mass spectrum of CH₃CCo₃(CO)₉ include the bare polymetallic ions [Co_n]⁺ (n = 3 and 2). Many examples of the elimination of neutral CO, C₂H₂ and H₂ fragments were noted in this work.     

Thallium(I), Silver(I), and Mixed Thallium(I)/Copper(I) Clusters with Bridging {Me2Si(N‐C6H4‐2‐SPh)2}2– Ligands

The S‐functionalized aminosilane Me₂Si(NH‐C₆H₄‐2‐SPh)₂ (H₂L) ( 1 ) was prepared from dichlorodimethylsilane and lithiated 2‐(phenylthio)aniline. Treatment of compound 1 with two equivalents of n‐butyllithium led to the dilithium derivative Li₂L, which was used in subsequent reactions with MCl (M = Tl, Cu, Ag) to prepare the complexes [Tl₂L] ( 2 ), [Cu₂Tl₂L₂] · 2THF ( 3a ), [Cu₂Tl₂L₂(THF)₂] ( 3b ), and [Ag₄L₂(THT)₂] ( 4 ) (THT = tetrahydrothiophene). Compound 2 consists of two thallium atoms, which are connected by a L^2– ligand to give a puckered Tl₂N₂ ring with Tl–N distances of 255(1)–268(1) pm. Compounds 3a and 3b are heterobimetallic complexes, which are based on [Cu₂L₂]^2– cores featuring a Cu₂N₄Si₂ ring with linearly coordinated copper atoms [Cu–N: 190.7(3)–192.5(3) pm] and two peripherally attached Tl atoms [Tl–N: 272.7(3)–281.9(3) pm]. The molecular structure of the tetranuclear silver(I) complex 4 is closely related to the structure of compounds 3a and 3b by replacement of the Cu and Tl atoms with Ag atoms. The Ag–N distances are 217.5(3)–245.7(3) pm.     

Bis(cyclopentadienyl)methan-verbrückte Zweikernkomplexe,V. Heteronukleare Co/Rh-, Co/Ir-, Rh/Ir- und Ti/Ir-Komplexe mit dem Bis(cyclopentadienyl)methan-Dianion als Brückenliganden

Bis(cyclopentadienyl)methane-bridged Dinuclear Complexes, V^[1]. – Heteronuclear Co/Rh-, Co/Ir-, Rh/Ir-, and Ti/Ir Complexes with the Bis(cyclopentadienyl)methane Dianion as Bridging Ligand^* The lithium and sodium salts of the [C₅H₅CH₂C₅H₄]^- anion, 1 and 2 , react with [Co(CO)₄I], [Rh(CO)₂Cl]₂, and [Ir(CO)₃Cl]n to give predominantly the mononuclear complexes [(C₅H₅-CH₂C₅H₄)M(CO)₂] ( 3, 5, 7 ) together with small amounts of the dinuclear compounds [CH₂(C₅H₄)₂][M(CO)₂]₂ ( 4, 6, 8 ). The ¹H- and ¹³C-NMR spectra of 3, 5 , and 7 prove that the CH₂C₅H₅ substituent is linked to the π-bonded ring in two isomeric forms. Metalation of 5 and 7 with nBuLi affords the lithiated derivatives 9 and 10 from which on reaction with [Co(CO)₄I], [Rh(CO)₂Cl]₂, and [C₅H₅TiCl₃] the heteronuclear complexes [CH₂(C₅H₄)₂][M(CO)₂][M′(CO)₂] ( 11–13 ) and [CH₂(C₅H₄)₂]-[Ir(CO)₂][C₅H₅TiCl₂] ( 17 ) are obtained. Photolysis of 11 and 12 leads almost quantitatively to the formation of the CO-bridged compounds [CH₂(C₅H₄)₂][M(CO)(μ-CO)M′(CO)] ( 14, 15 ). According to an X-ray crystal structure analysis the Co/Rh complex 14 is isostructural to [CH₂(C₅H₄)₂][Rh₂(CO)₂(μ-CO)] ( 16 ).     

Some binuclear complexes of iron and cobalt with isocyanide ligands

Whereas Co₂(CO)₈ and RNC (R= Me, Et, and Cy) react to give mixtures of [(RNC)₅Co] [Co(CO)₄] and the covalent, carbonyl-bridged [(RNC)_mCo₂(CO)_8?m] derivatives (m = 1–3), [(π-dienyl)Fe(CO)₂]₂ give only [(π-dienyl)₂Fe₂(CO)_4?n(CNR)_n] complexes (dienyl = C₅H₅, MeC₅H₄ and C₉H₇; n = 1–2) that exist in solution as mixtures of cis- and trans-CO- and RNC-bridged tautomers with the μ-RNC species decreasing in importance as the bulk of R increases.     

Zur verwendung von ferricenium-kationen als selektivem oxidationsmittel in der metallorganischen chemie

The use of ferricenium cations [(C₅H₅)₂FE]X (X = BF₄, PF₆, SbF₆) as one-electron oxidizing agents for organometallic complexes is demonstrated. Sandwich compounds M(C₅H₅)₂ (M = Cr, Co, Ni) and Cr(C₆H₆)₂ are oxidized in nearly quantitative yield to the corresponding cations [M(C₅H₅)₂]BF₄ and [(C₆H₆)₂Cr]BF₄. The metalmetal bond in the dinuclear organometallic complexes [DienylM(CO)_n]₂ (M = Mo (n = 3), Fe (n = 2), Ni (n = 1)) and Co₂(CO)₈ is fissioned by (C₅H₅)₂Fe⁺ in the presence of neutral ligands L to form the corresponding cationic compounds [DienylM(CO)_nL_m]X (M = Mo (n = 2), Fe (n = 2), Ni (n = 0)) and [Co(CO)₃L₂BF₄ (L = VB and VIB donor ligands) in high yields.The practical applications of ferricenium cations are discussed in comparison with other methods for the preparation of cationic organometallic complexes.     

Photoinduced synthesis of the mixed metal “manganese rhenium cubane” [Mn3Re(CO)12(SC6H5)4]

The photoinduced synthesis and spectroscopic properties of the new mixed metal compound [Mn₃Re(CO)₁₂(SC₆H₅)₄] by UV irradiation of a mixture of Mn₂(CO)₁₀, Re₂(CO)₁₀ with S₂(C₆H₅)₂ is described. No mixed sulphur/selenium compounds [M₄(CO)₁₂S_nSe_4?n(C₆H₅)₄] (M = Mn or Re, n = 1–3) could be obtained by analogous photoreactions.     

Decacarbonylbis(methylcyclopentadienyl)‐tetrahedro‐diiridiumdimolybdenum and decacarbonylbis(tetramethylcyclopentadienyl)‐tetrahedro‐diiridiumdimolybdenum dichloromethane hemisolvate

The two title compounds, [Mo₂Ir₂(C₆H₇)₂(CO)₁₀] and [Mo₂Ir₂(C₉H₁₃)₂(CO)₁₀]·0.5CH₂Cl₂, respectively, or collectively [Mo₂Ir₂(μ‐CO)₃(CO)₇(η⁵‐C₅H_5?nMe_n)₂] (n = 1 or 4), have a pseudo‐tetrahedral Mo₂Ir₂ core geometry, an η⁵‐­C₅H_5?nMe_n group ligating each Mo atom, bridging carbonyls spanning the edges of an MoIr₂ face and seven terminally bound carbonyl groups.