Reactions of transition metal compounds with macrocyclic alkadiynes : IV*. Intramolecular transannular cyclizations with cyclopentadienyldicarbonylrhodium

The macrocyclic alkadiynes, 1,7-cyclododecadiyne, 1,7-cyclotridecadiyne, 1,7- and 1,8-cyclotetradecadiyne, and 1,8-cyclopentadecadiyne react with C₅H₅Rh(CO)₂ in boiling cyclooctane to give pale yellow to white volatile compounds of the compositon C₅H₅Rh(alkadiyne) in which the macrocyclic alkadiyne has undergone an intramolecular transannular cyclization to form a tricyclic cyclobutadiene derivative. The reaction of 1,7-cyclododecadiyne with C₅H₅Rh(CO)₂ also gives a dimer of 1,7-cyclododecadiyne containing a benzene ring. Corresponding reactions of the simple alkynes RCCR (R = C₂H₅ and C₆H₅) with C₅H₅Rh(CO)₂ in boiling cyclooctane failed to give any rhodium—cyclobutadiene derivatives. Instead the reaction of 3-hexyne with C₅H₅Rh(CO)₂ under these conditions gave orange-red (C₅H₅)₂Rh₂(CO)C₄(C₂H₅)₄ and purple-black (C₅H₅)₃Rh₃(CO)(C₂H₅CCC₂H₅) and the reaction of diphenylacetylene with C₅H₅Rh(CO)₂ gave a low yield of the orange complex (C₅H₅)₃Rh₃(C₆H₅CCC₆H₅). The infrared, ¹H NMR, and mass spectra of these new cyclopentadienylrhodium complexes are described.     

Regiospecificity in the reaction of [Fe2(η-C5H5)2(CO)4-n(CNMe)n] (n  02) with mercury(II) halides

The reactions of [Fe₂(η-C₅H₅)₂(CO)₂(L)(CNMe)] (L  CO or CNME) with HgX₂ (X  Cl, Br or I) give [Fe(η-C₅H₅)(CO)₂HgX] and [Fe(η-C₅H₅)(L)-(CNMe)X] as the sole products in ca. quantitative yields; this is consistent with the previously proposed mechanism for the reactions of electrophiles with polynuclear metal carbonyl derivatives.     

Facial coordination of cyclooctatetraene to a Co2Ni triangle in a heterometallic trinuclear cluster complex

Reaction of [(η-C₅H₅)NiCo₃(CO)₉] (5) with 1,3,5,7-cyclooctatetraene or 1,4-(SiMe₃)₂C₈H₆, respectively, yields the complexes [Co₂Ni(CO)₆(μ₃-η⁸-C₈H₆R₂)] (R=H, SiMe₃) (7a, b). Dramatic modifications of the tetrametallic cluster core and the ligand sphere of 5 to give the trinuclear complex 7 are driven by the preference of the cyclopolyenes for facial (μ₃-η⁸) coordination. The title complexes are the first examples of facial cyclooctatetraene coordination to a heterometallic (Co₂Ni) triangle.     

Rational design and syntheses of 0-D, 1-D, and 2-D metal-organic frameworks (MOFs) from ferrocenedicarboxylate tetrametallic macrocyclic building units and subsidiary ligands

We have designed and synthesized three new metal-1,1′-ferrocenedicarboxylate complexes containing tetrametallic macrocyclic building units, namely, [Cd₂(η²-O₂CFcCO₂-η²)₂(phen)₂(H₂O)₂] · 4CH₃OH (1) (Fc = (η⁵-C₅H₄)Fe(C₅H₄-η⁵), phen = 1,10-phenanthroline), {[Cd(η²-O₂CFcCO₂)(pebbm)(H₂O)] · 2H₂O}_n (2) (pebbm = 1,1′-(1,5-pentanediyl)bis-1H-benzimidazole) and {[Cd(η²-O₂CFcCO₂-η²)(prbbm)(H₂O)] · 3H₂O}_n (3) (prbbm = 1,1′-(1,3-propanediyl)bis-1H-benzimidazole). Compound 1 is a 0-D discrete tetrametallic macrocyclic framework. Compound 2 features an infinite 1-D ribbon of rings structure constructed by the subsidiary ligands pebbm connecting tetrametallic macrocyclic building units. For 3, its tetrametallic macrocyclic building units are linked by the subsidiary ligands prbbm to form a 2-D network structure. The structural features of these complexes indicate that the ferrocenedicarboxylate tetrametallic macrocycle can be used as a successful molecular building unit and the shapes and conformational flexibility of subsidiary ligands play a crucial role in the manipulation of the configuration of the resultant MOFs. Their fluorescence spectra in solid state at room temperature suggest that the fluorescence emissions of 1-3 are ruled by 1,1′-ferrocenedicarboxylate ligand.     

Reactive intermediates in the photolysis of cyclopentadienylcobalt(I) dicarbonyl and in the reduction of cyclopentadienylcobalt(III) carbonyl diiodide

Photolysis of (C₅H₅)Co(CO)₂ (I) in toluene or petroleum ether solution at ?78°C generates the unsaturated monocarbonyl species (C₅H₅)Co(CO), which was identified in solution by its IR spectrum. At room temperature, this monocarbonyl can associate with excess I to give (C₅H₅)₂Co₂(CO)₃, or dimerize to (C₅H₅)₂Co₂(CO)₂. The latter is stable as a solid, but in solution it is slowly converted to the insoluble trimer (C₅H₅)₃Co₃(CO)₃. (C₅H₅)₂Co₂(CO)₂ is symmetrically cleaved by phosphines to (C₅H₅)Co(CO)(PR₃), while diolefins bring about unsymmetrical cleavage to give (C₅H₅)Co(diolefin) and (C₅H₅)Co(CO)₂.     

From straight chain to macrocyclic complexes containing mixed sulfur/nitrogen donors and coordinated 1,3-diynes

The acid-mediated reaction of [{Co₂(CO)₆(μ-η²-HOCH₂CC-)}₂] (1) with the meta- and para-substituted aminothiophenols, 3-NH₂-C₆H₄SH and 4-NH₂-C₆H₄SH, affords the straight chain species, [{Co₂(CO)₆(μ-η²-(3-NH₂-C₆H₄S)CH₂CC-)}₂] (2) and [{Co₂(CO)₆(μ-η²-(4-NH₂-C₆H₄S)CH₂CC-)}₂] (3), respectively. The molecular structure of 3 reveals the presence of two isomeric forms differing in the relative disposition of the S-aryl groups. Conversely, reaction of 1 with the ortho-substituted aminothiophenol, 2-NH₂-C₆H₄SH, furnishes the 10-membered macrocyclic species [{Co₂(CO)₆}₂{cyclo-μ-η²:μ-η²-CH₂C₂C₂CH₂SC₆H₃-NH-2}] (4) along with the linear chain complex [{Co₂(CO)₆(μ-η²-(2-NH₂-C₆H₄S)CH₂CC-)}₂] (5). On the other hand, treatment of 1 with the ortho-substituted mercaptopyridine, 2-SH-C₅H₄N, in the presence of HBF₄ gives the salt [{Co₂(CO)₆(μ-η²-(2-S-C₅H₄NH)CH₂CC-)}₂](BF₄)₂ (6a) in good yield; work-up in the presence of base affords the neutral complex [{Co₂(CO)₆(μ-η²-(2-S-C₅H₄N)CH₂CC-)}₂] (6b). Single crystal X-ray diffraction studies have been reported on 3-5 and 6a.     

Comparative studies of the photochemical and thermal reactivities of the molybdenum-molybdenum single bond in [Mo2(η5-C5H5)2(CO)6] and triple bond in [Mo2(η5-C5H5)2(CO)4] towards nitrite and nitrate

Irradiation at λ = 507 and 391 nm of [Mo₂(η⁵-C₅H₅)₂(CO)₆] in a degassed tetrahydrofuran (THF) or THF-MeOH solution containing nitrite gives [Mo(η⁵-C₅H₅)₂NO] and several oxo complexes including [{Mo(η⁵-C₅H₅)(O)₂}₂O] in good yields. The quantum yields for the disappearance of [Mo₂(η⁵-C₅H₅)₂(CO)₆] in the reaction with NO₂⁻ depend on the nitrite concentration, thus suggesting participation of the metal-radical intermediate in the reduction of nitrite. Reactions of [Mo₂(η⁵-C₅H₅)₂(CO)₄] with nitrite or nitrate in the dark give the same nitrosyl and oxo complexes as above. An oxygen atom in nitrite or nitrate is mainly transferred onto the molybdenum atom both in the photochemical and the dark reactions.     

The preparation of a series of ring-linked derivatives of [Fe2(η-C5H5)2(CO)2(μ-CO)2] starting from [Fe2η5,η5-C5H4CH(NMe3)CH(NMe2)C5H4}(CO)2(μ-CO)2]+ salts

The salts [Fe₂η⁵,η⁵-C₅H₄CH{NMe₃)CH(NMe₂)C₅H₄}(CO)₂(μ-CO)₂][X] (X = I or SO₃CF₃) are the synthetic precursors to a wide range of [Fe₂(η-C₅H₅)₂(CO)₂(μ-CO)₂] derivatives in which the two cyclopentadienyl ligands are joined by a two-carbon bridge.     

Synthesis and Characterizations of Ferrocenyl Carbonyl Chromium and Cobalt Clusters

Two novel bimetallic complexes, [Cr(CO)₃(η ⁶-C₆H₅)–C≡C–C₆H₄–Fc] (Fc = C₅H₅FeC₅H₄] (1) and [Cr(CO)₃(η ⁶-C₆H₅)–C ≡ C–Fc–C(CH₃)₂–Fc] (3), were synthesized by the Sonogashira coupling reaction. By using of (1) and (3) as ligands to react with Co₂(CO)₈, two others novel polymetallic complexes, [Cr(CO)₃(η ⁶-C₆H₅){Co₂(CO)₆-η ²-μ ²-C≡C–}–C₆H₄–Fc] (2) and [Cr(CO)₃(η ⁶-C₆H₅){Co₂(CO)₆-η ²-μ ²-C≡C–}Fc–C(CH₃)₂–Fc] (4) were obtained. Four carbonyl complexes were characterized by elemental analysis, FT-IR, NMR and MS. The molecular structures of complexes (1), (2) and (4) were determined by single crystal X-ray diffraction. The interactions among the ferrocenyl, Cr(CO)₃ and Co₂(CO)₆-η ²-μ ²-C≡C– units were investigated by cyclic voltammetry.     

Synthesis of μ-hydrido-μ-phosphido heterotrimetal alkylidyne clusters: X-ray crystal structure of [Co2W(μ-H)(μ3-CMe)(μ-PPh2)(CO)6(η-C5H5]

Treatment of the μ-alkylidyne clusters [Fe₂W(μ₃-CC₆H₄Me-4)(μ-CO)- (CO)₈(η-C₅H₅)] and [Co₂W(μ₃-CMe)(CO)₈(η-C₅H₅)] with PPh₂H affords a series of new μ-phosphido-μ-hydrido alkylidyne complexes which undergo protonation with HBF₄·Et₂O to give cationic derivatives. The X-ray structure of [Co₂W(μ-H)(μ₃-CMe)(μ-PPh₂)(CO)₆(η-C₅H₅)] has been determined.     

Mass spectra of cobalt carbonyl complexes

The mass spectra of the following acetylenic derivatives of Co₂(CO)₈ are reported: Co₂(CO)₆C₂H₂Co₂(CO)₆C ₂,(CH₃)₂, Co₂(CO)₆ C₂(CH₂Cl)₂, Co₂(CO)₆C₂ (CF₃)₂, Co₂(CO)₂C₂(C₆H₅)₂ and Co₂(CO)₆C₂(COOCH₃)₂. The effect of different C₂RR′ on fragmentation modes is investigated. When R and R′ are aromatic groups, the major controlling factor is the stability of charged fragments; in other cases, it seems to be the loss of a stable neutral moiety. Transfer processes of alkoxylic groups are observed in Co₂(CO)₆C₂(COOCH₃)₂, as well as in Co₃(CO),₉CCOOCH₃, and Co₃(CO)₉CCOOC₂H₅. It is suggested that both cobalt and carbon atoms may be the migration sites.     

Reactions of metal carbonyl derivatives : XIV. Bridged phosphido derivatives of iron and ruthenium

The tertiary phosphines P(C₆H₅)₂R [RM π-C₅H₅)(CO)₂ M(π-C₅H₅(CO)₂ (M = Fe or Ru)] readily effect the displacement of the chloro group in [M′(φ-C₅H₅)(CO)₂Cl] (M′ = Fe or Ru) to give bridged cationic species of the type [MM′(φ-C₅H₅)₂(CO)₄P(C₆H₅)]⁺. Treatment of [Fe₂(CO)₉] with P(C₆H₅)₂R [RRu(φ-C₅H₅)(CO)₂] leads to the formation of the neutral mixed-metal derivatives [FeRu(φ-C₅H₅)(CO)₆P(C₆H₅)₂] and [FeRu(φ-C₅H₅)(CO)₅P(C₆H₅)₂].     

Reactions of metal carbonyl derivatives X. The synthesis and reactivity of some dinuclear derivatives of iron containing both bridging carbonyls and bridging phosphido or sulphido groups

The tertiary phosphine π-C₅H₅Fe(CO)₂P(C₆H₅)₂ reacts with a suspension of Fe₂(CO)₉ in benzene to give the dinuclear complex π-C₅H₅Fe₂P(C₆H₅)₂(CO)₆. This compound is also obtained by nucleophilic attack of [π-C₅H₅Fe(CO)₂]⁻ on Fe(CO)₄-[P(C₆H₅)₂Cl] in tetrahydrofuran. Irradiation of a benzene solution of π-C₅H₅Fe₂-P(C₆H₅)₂(CO)₆ with ultraviolet light affords π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅ which contains both a bridging carbonyl and a bridging phosphido group. The unstable bridged sulphido derivatives π-C₅H₅Fe₂SR(CO)₆ (R = CH₃ and C₆H₅) and π-C₅H₅Fe₂(t-C₄H₉S)(CO)₅ are similarly obtained employing π-C₅H₅Fe(CO)₂SR as ligand. The reactions of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅ with tertiary phosphines and phosphites yield three types of products depending on the reaction conditions and the ligand involved. Examples include π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄P(C₆H₅)₃, a mono-substituted derivative of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅, and π-C₅H₅Fe₂P(C₆H₅)₂(CO)₅P(C₂H₅)₃ and π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄[P(OCH)₃)₃]₂, mono- and bis-substituted derivatives of π-C₅H₅Fe₂P(C₆H₅)₂(CO)₆, respectively. The reaction of π-C₅H₅Fe₂P(C₆H₅₂(CO)₅ with (C₆H₅)₂PCH₂P(C₆H₅)₂ in benzene under reflux affords [π-C₅H₅Fe₂P(C₆H₅)₂(CO)₄](C₆H₅)₂PCH₂P(C₆H₅)₂ in which the ditertiary phosphine bridges two iron atoms.     

The reactions of [Co(η-C5H5)(CO)(L)] (L = R3P or RNC) with carbon disuphide and organoisothiocyanates

The reactions of [Co(η-C₅H₅)(CO)(PR₃)] or [Co(η-C₅GH₅)(CO)₂]/R₃P mixtures (R = alkyl or aryl) with CS₂ in refluxing CS₂ or CS₂/toluene gives rise to [Co(η-C₅H₅)(PR₃)(CS)], [Co(η-C₅H₅)(PR₃)(CS₂)], [Co(η-C₅H₅)(PR₃)(CS₃)], and [Co₃(η-C₅H₅)₃ (CS)(S)] in reasonable yields. The corresponding reactions using PhNCS give [Co(η-C₅H₅)(PPh₃)(PhNCS)] and a polymeric species which appears to be [Co₄(η-C₅H₅)₄ (PhNCS)]. Similar products are obtained with [Co(η-C₅H₅)(CO)(CNR)] or [Co(η0C₅H₅)(CO)₂]/RNC mixtures.     

Synthesis and properties of Zr-Co heterodinuclear complexes with a bridging bis(cyclopentadienyl) ligand

[(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(C₅H₅)] reacted with Co₂(CO)₈ to produce a heterodinuclear Zr(IV)-Co(I) complex [(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(η⁵-C₅H₄)Co(CO)₂] (3). Complex 3 underwent oxidative addition of I₂ to give [(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(η⁵-C₅H₄)CoI₂(CO)] (4) having Zr(IV) and Co(III) centers. The carbonyl ligand of 4 was easily replaced with P(OMe)₃ and PPh₃ to afford [(η⁵-C₅H₅)ZrCl₂(η⁵-C₅H₄)CMe₂(η⁵-C₅H₄)CoI₂(L)] (5: L = P(OMe)₃, 6: L = PPh₃). Structures of 5 and 6 were determined by X-ray crystallography. These Zr-Co heterodinuclear complexes catalyzed polymerization of ethylene and propylene.     

Isonitrilsynthesen am komplex: V. Desulfurierung von isothiocyanaten in carbonylmetallat-additions-verbindungen

The isocyanide complexes [Fe(η-C₅H₅)(CO)₂CNR][PF₆] and Cr(CO)₅CNR (R = CH₃, C₆H₁₁, C₆H₅) are conveniently prepared at ?50°C from carbonyl metallates, isothiocyanates, and phosgene. At room temperature Na[Fe(η-C₅H₅)(CO)₂] reacts with isothiocyanates ($\text{1}\text{1}$) to give the isocyanide bridged complexes [Fe₂(η-C₅H₅)₂(μ-CO)(μ-CNR)(CO)₂].     

Modeling of the molecular and electronic structures of some mono- and biosmium complexes of fullerene C60

The modeling of the molecular and electronic structures of the following mono- and biosmium complexes of fullerene C₆₀ was performed by quantum chemical methods (MNDO/PM3 and DFT/PBE): (??²-C₆₀)[Os(PPh₃)₂(CO)CNMe], (??²,??²-C₆₀)[Os(PPh₃)₂(CO)(CNMe)]₂, (??²-C₆₀)[Os(PH₃)₂(CO)H], (??²,??²-C₆₀)[Os(PH₃)₂(CO)H]₂, (??²-C₆₀)[Os(PH₃)₂(CO)CNMe], (??²,??²-C₆₀)[Os(PH₃)₂(CO)CNMe]₂, and (5-C₆₀H₅)[Os(C₅H₅)], (5, 5-C₆₀H₁₀)[Os(C₅H₅)]₂.The osmium atoms in the first six complexes are ??²-coordinated by fullerene C₆₀. In the last two complexes, the ??⁵-coordination mode is observed. The structures of the radical anions of these complexes were calculated. The energies of the frontier orbitals were evaluated. The acceptor properties of the complexes are discussed. The electron affinities were estimated in two ways: from the energy of the lowest unoccupied molecular orbital (LUMO) and as the energy difference between the neutral molecule and its radical anion.     

SYNTHESIS OF HIGHER-NUCLEARITY CLUSTERS BY ASSEMBLING THE -CCo3(CO)9 UNITS INTO AROMATIC SPACER MOLECULES

Abstract

p-[(CO)₉Co₃C]₂C₆H₄ (1) has been synthesized by reacting Co₂(CO)₈ with p-(Cl₃C)₂C₆H₄. 4,4′-[(OC)₉Co₃CC(O)]C₆H₄-C₆H₄[C(O)CCo₃(CO)₉] (2) has been synthesized from p-LiC₆H₄-C₆H₄Li and BrCCo₃(CO)₉. Similarly m-[(OC)₉Co₃CC(O)CH₂]₂C₆H₄ (3) has been synthesized from m-(LiCH₂)₂C₆H₄ and BrCCo₃(CO)₉. X-ray analysis was done for 1 and 2; both compounds exhibit a stacked structure. Cyclic voltammetry and UV spectra revealed usual behavior for 1, that is, two cluster units interact strongly through the benzene spacer, which is not the case for clusters 2 and 3.     

Acetylenic derivatives of metal carbonyls of the triad Fe,Ru, Os—XI Mass spectra of some binuclear complexes

The mass spectra of the following acetylenic derivatives of iron, ruthenium and osmium carbonyls are reported: the iron compounds Fe₂(CO)₆[C₂(C₆H₅)s₂]₂, Fe₂(CO)₆[C₂(CH₃)₂]₂ and Fe₂(CO)₆[C₂(C₂H₅)₂]₂, the ruthenium compounds Ru₂(CO)₆[C₂(C₆H₅)₂]₂, and Ru₂(CO)₆[C₂(CH₃)₂]₂ and the osmium compounds Os₂(CO)₆[C₂(C₆H₅)₂]₂, Os₂(CO)₆[C₂HC₆H₅]₂ and Os₂(CO)₆[C₂(CH₃)₂]₂. Iron compounds exhibit breakdown schemes where binuclear, mononuclear and hydrocarbon ions are present. On the other hand, ruthenium and osmium compounds fragment in a similar way and give rise to singly and doubly charged binuclear ions. Phenylic derivatives of ruthenium and osmium also give weak triply charged ions. The results are discussed in terms of relative strengths of the metal-metal and metal-carbon bonds.     

Die thermische reaktion von C5H5(CO)2FeNa mit benzimidchloriden C6H5(Cl)CNR

η⁵-C₅H₅(CO)₂FeNa reacts with the benzimide chlorides C₆H₅(Cl)CNR (R  CH(CH₃)₂, C₆H₅) in boiling THF to give the η¹-iminoacyl complexes η⁵-C₅H₅ (CO)₂Fe[η¹-C(C₆H₅)NR]. Alternatively, the new Fe complexes [η⁵-C₅H₅(CO)Fe$\text{C(C}{}_6\text{H}{}_5\text{)N(CH}{}_3\text{)C(C}{}_6\text{H}{}_5\text{)N}$CH₃PF₆ (IV) and [η⁵-C₅H₅(CO)₂FeC(C₆H₅)N(CH₃)C(C₆H₅)NCH₃]PF₆ (V) are formed under the same conditions, if R  CH₃. Hudrolysis of the CN single bond of the ligand in V, not stabilized by a chelate effects as in IV, results in the formation of [η⁵-C₅H₅(CO)₂FeC(C₆H₅)NHCH₃]PF₆ (VII). Reaction of η⁵-C₅H₅(CO)₂ with N-benyzylbenzimido chloride yields η⁵-C₅H₅(CO)₂FeCH₂C₆H₅ as the only isolated product.