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We report on a breast carcinoma with medullary features diagnosed by core needle biopsy in a 72-year-old woman. Both the primary tumour and its fine needle aspiration-proven, rapidly growing axillary metastasis regressed completely in less than 2 months, by the time surgery was performed. The biopsy of the primary tumour demonstrated a dense stromal infiltrate of CD8+/granzyme B+ activated cytotoxic T-cells suggestive of a robust antitumour immune response. Paradoxically, both tumour cells and tumour infiltrating immune cells demonstrated a diffuse PD-L1 expression, revealing that antitumour immune response has the ability to spontaneously overcome inhibitory mechanisms induced by cancerous growth.

The optimal locoregional treatment of patients diagnosed with sentinel node (SN) micrometastasis is controversial. A previously reported and validated nomogram was used to calculate the risk of non-SN metastasis in patients with SN micrometastasis over a period of 2 years. Patients were given detailed information about the risk, consequences and treatment options of non-SN involvement, the risk and potential complications of unnecessary completion axillary lymph node dissection (ALND), the imperfectness of the nomogram, and other factors that may influence their selection of further treatment. They also received a questionnaire to monitor factors influencing their decisions. Of the 25 patients participating in the study, 10 have opted for ALND. The only factor that seemed to influence their choice was fear from disease recurrence. Giving detailed information to SN micrometastatic patients is a patient-centered alternative to current recommendations on performing ALND in all such patients or omitting ALND in all of them.

Colorectal carcinomas (CRCs) infiltrating through the muscularis propria layer without infiltration of adjacent structures, organs or the serosa-i.e. the pT3 tumors, compose the largest subset of large intestinal carcinomas treated by surgical resection. They are heterogeneous in terms of prognosis. CRCs treated by surgery in a period of 69 months were prospectively classified as pT3a tumors (invading to a maximum of 5 mm beyond the muscularis propria) and pT3b tumors (invading deeper). Their nodal status, incidence of vascular invasion and the presence or absence of distant metastases were analyzed in relation to the depth of invasion. Of the 593 CRCs primarily treated by surgery 429 were pT3 tumors. CRCs categorized as pT3a had significantly lower rates of nodal involvement (44% vs 75%), massive nodal involvement (pN2) (9% vs 39%), venous invasion (17% vs 30%) and distant metastasis (11% vs 28%) than pT3b tumors. Significant differences in these prognostic variables in pT3a and pT3b cancers were observed both for carcinomas of the colon and those of the rectum. Such differences were not obvious in further 66 ypT3 cases of rectal carcinoma receiving neoadjuvant treatment before surgery. Tumors in the pT3a category are associated with a better prognostic profile than pT3b tumors. This subdivision might be useful in both prognostication and treatment planning.

The complexes Co3(CO)9(μ3-X) (X=S, Se) can be reduced to the corresponding anionic species [Co3(CO)9(μ3-X)]−, which react with allyl bromide to give Co3(CO)7(μ-η3-C3H5)(μ3-X) (X=S, Se). These are the first two cobalt complexes containing the bridging μ-η3-allyl ligand. The structure of the selenium complex was determined by X-ray crystallography. Crystal data for Co3(CO)7(μ-η3-C3H5)(μ3-Se) are as follows: space group P21/c, a=9.051(2) A, b=8.102(2) A, c=21.27(4) A, β=93.82(3)°, Z=4, and R=0.0565 for 2491 observed reflections.

The paramagnetic Co3(CO)9(μ3−S) cluster (1) reacts with organic compounds containing S−H, S−S, or P−H bonds to give diamagnetic Co3(CO)7(μ-X)(μ3−S) (μ-X = (μ-L, μ-(1,2-η)-L, and μ-(1,3-η)-L) complexes. The reaction was used to prepare the derivatives with μ-L = SR (2a−h; R = Et, t-Bu, CH2Ph, allyl, Ph, C6F5, 2-naphthyl, CH2CH2OH) and PPh2 (7), μ-(1,2-η)-L = P(S)Ph2 (8), and μ-(1,3-η)-L = S2CR (R = SMe (4), OMe (5), Ph (6)). The reaction results in an increase of the oxidation state of cobalt and may be therefore called an oxidative substitution. It is the first successful and rational way to prepare derivatives of Co3(CO)9(μ3-S), a fundamental cluster molecule described in 1961. The crystal structures of the triphenylphosphine-substituted derivative of 2b, Co3(CO)4(PPh3)3(μ-S-t-Bu)(μ3-S) (3), and of 4, 6, and 8 were determined. A new, high-yield synthesis of 1 is described.

Dicobalt octacarbonyl reacts with an excess of (MeSCS2)2 to form several sulfur-containing cobalt carbonyl derivatives; on addition of PPh3, the complex Co2(CO)2(PPh3)2(1,3-η-S2CSMe)(μ-1,2-η-SCSMe) (1) could be isolated from the reaction mixture. The structure of complex 1 was determined by X-ray crystallography; it contains a methyl dithioformate ligand in which the ligand donates five electrons to the cluster and the CS group is bound perpendicular to the Co2 core.

Sentinel lymph node biopsy (SLNB) is a standard procedure in women with breast cancer. The risk of morbidity related to axillary lymph node dissection (ALND) is similar for men and women with breast cancer and SLNB could minimize this risk.Between January 2004 and August 2013, 25 men with primary breast cancer were operated on at the Bács-Kiskun County Teaching Hospital. These were reviewed retrospectively. SLNB was performed following lymphoscintigraphy with intraoperative gamma probe detection and blue dye mapping.SLNB was successful in all 16 male patients (100 %), in whom it was attempted. The SLNs were negative in 4 cases (25 %) and were involved in 12. Intraoperative imprint cytology was positive in 9 of the 12 involved cases (75 %) and resulted immediate completion ALND. In 7 patients, the intraoperative imprint cytology was negative, with 3 false-negative results that resulted in delayed completion ALND. After a median follow-up of 48 months, there was only one axillary recurrence after ALND and none in the SLNB group.SLNB is successful and accurate in male breast cancer patients too. Although compared to women a larger proportion of men have positive nodes, for men with negative nodes, ALND-related morbidity may be reduced by SLNB. We recommend SLNB in male patients with breast cancer and clinically negative axilla.

Dicobalt octacarbonyl and perfluoro diphenyl disulfide react to form Co3(μ3-S) (C6F5)(CO)8 (1), an unusual cobalt carbonyl cluster containing an aryl-metal sigma bond. The structure of complex 1 was determined by X-ray crystallography; it crystallizes in triclinic P-1 space group with a = 8.218(2), b = 13.379(2), c = 18.864(2) A, α = 106.96(2), β = 96.91(2), γ = 97.39(2)°. The final R is 0.0376 for 5286 observed reflections (F0>4.0σF0).

The complex (1) has been prepared and its structure determined. Complex1 is the first stable thioether derivative of a metal carbonyl containing only cobalt as metal. It crystallizes in the monoclinic P21/c space group, witha = 13.975( 4 ),b = 11.363( 3 ),c = 14.686(2)A,β = 112.25(2)°,V = 2158.5(7)A3.Z = 4. The solution using direct methods and the anisotropic refinement of all nonhydrogen atoms led toR = 0.039,wR = 0.041 for 3296 reflections with F> 4.0σ(F) Analogous but less stable complexes are formed with 1,6-diphenyl-2,5-dithiahexane and the crown thioether 1,4,7-trithiacyclonane, the latter functioning either as a bidenlate or a tridentate ligand.

Hydroxycarbonylation of benzyl and substituted benzyl chloride and bromide derivatives was achieved in good yields (up to 97.6%) and quantitative chemoselectivity, in the presence of Co2(CO)8 as the transition metal and polyethylene glycols as the phase-transfer catalyst in an organic solvent/20% aqueous NaOH two-phase system under mild conditions (1 bar CO, room temperature). η1-Benzyl-, η3-benzyl-, and (η1-phenylacetyl)cobalt carbonyls were investigated as intermediates of this catalytic process.

Several diamine-substituted cobalt carbonyl butenolide complexes of the type Co2(H,R,C4O2)(μ2-CO)(CO)4(LL) [R = H or nBu; (LL) = N,N,N′,N′-tetramethylethylenediamine (tmeda), 1,2-diamino cyclohexane (dach) cis- and trans-isomers, o-phenylene diamine (opda), 1,10-phenanthroline (phen), or 2,2′-dipyridyl (dipy)] have been prepared. The structures of three representatives [R = H, (LL) = tmeda (1); R = nBu, (LL) = phen (8b) and dipy (9)] have been determined. Complexes 1, 8b and 9 crystallise in triclinic P1 (a = 7.442(2), b = 9.159(2), c = 14.182(3) A, α = 79.34(3), β = 82.34(3), γ = 7.07(3)°), monoclinic P21/c (a = 10.953(2), b = 16.464(4), c = 14.537(3) A, β = 110.47(2) °) and monoclinic P21/n (a = 9.698(6), b = 15.508(6), c = 15.966(8), A, β = 79.30(4)°) space groups, respectively. The complexes with tmeda and trans-dach are the first stable cobalt carbonyl derivatives containing saturated aliphatic amines as ligands.

The reactions of Co2(CO)8 with asymmetrically substituted alkynes lead to derivatives Co2(CO)6(RC2R′) (1). Substitution reactions of complexes 1 with PPh3, Ph2P · CH2CH2 · AsPh2 (arphos) and Ph2P · CH2 · PPh2 (dppm) have been attempted. With PPh3 monosubstituted chiral tetrahedral molecules, characterized by two differently substituted acetylenic carbon atoms and by two cobalt atoms with different ligand arrangement have been obtained (complexes 2); some disubstituted derivatives have also been observed (complexes 3). The equatorial or axial position of the phosphines is discussed. With dppm bridged Co2(CO)4(dppm){PhCC·C(O)Me} (5) is obtained, whereas with arphos a chelate compound (4) is the main product. The complexes have been characterized by means of elemental analyses, mass spectrometry and spectroscopic techniques.

The rate of acetylcobalt tetracarbonyl methanolysis between 40 and 60 °C is first-order with respect to the acetylcobalt tetracarbonyl concentration and independent of the carbon monoxide concentration. The reaction is susceptible to both acid and base catalysis. Nucleophilic substitution of Co(CO) 4 on the acyl carbonyl-carbon by methanol is the most probable pathway.

Co2(CO)8 and Me2P(S)P(S)Me2 react to form the two cluster complexes: Co4(CO)9S(PMe2)2) (1) and Co3(CO)7S(SPMe2) (2). The strucure of1 and of the disubstituted triphenyl phosphine derivative of2. Co3(CO)5(PPh3)2S (SPMe3) (2a) were determined. Compound1 contains a quasi-planar rhomboidal Co4 cluster formed by two Co3 isosceles triangles sharing a Co-Co edge. One triangle is capped by a sulfur atom, the other triangle has two edge-bridging PMe2 moieties. Electron counting gives 64 electrons corresponding to a planar system; the distribution of long Co-Co distances, in particular in the triangle bearing PMe2 bridges, suggests that the excess electrons are located on Co-Co antibonding ortibals. Compound2a contains a Co3S cluster with one side bridged by a SPMe2 unit forming a four-membered Co2SP ring. The substitution of two CO groups with two PPh3 causes a large deformation of the cluster Co-Co bondscis to these two phosphorus atoms. Crystal data for1, space group P1,a = 9.728(2) A,b = 10.288(2) A,c = 11.860(3) A,α = 86.41(2)°,β = 76.20(2)°,γ = 80.37(5)°,Z = 2, 5300 reflections,R = 0.0398; for2a, space group P1,a = 9.78(3) A,b = 13.05(4) A,c = 18.28(6) A,α = 93.23(3)°,β = 99.17(2)°,γ = 97.26(6)°,Z = 2, 2976 reflections,R = 0.0579.

The hydrosilylation of carbon monoxide with cobalt carbonyls under relatively mild conditions resulted in a Fischer-Tropsch-analogous reductive coupling of CO. Alkyl silyl ethers, 1,2-bis(silyloxy)-1-alkenes and higher molecular weight compounds with at least three silyloxy groups were also formed, each of these containing up to seven carbon atoms derived from CO and for the most part having a linear structure. A (silyloxycarbyne)cobalt complex was postulated as the key intermediate.

It has been shown that (β-silyloxyacyl)cobalt tetracarbonyls are formed in the reaction between silylcobalt tetracarbonyl, terminal oxirane, and carbon monoxide. The linear acyl isomer is obtained with a regioselectivity of about 80%, which is practically independent of the nature of the substituents in the silyl group. Kinetic studies have revealed a first order dependence on Ph3SiCo(CO)4, an increasing order with respect to ethyloxirane, and zero order with respect to [Co(CO)4]− and CO. A mechanism involving a rapid formation of a tight ion pair, rate-determining internal SN2 type substitution, and fast insertion of CO is suggested.

The reaction of [Co 2 (CO) 8 ] with 1-phenylbut-1-yn-3-one in refluxing toluene yields [Co 2 (CO) 6 {μ-PhCCC(O)CH 3 }, the symmetrical trimer {PhC 2 C(O) CH 3 } 3 , which were characterized by spectroscopic techniques, and the title complex, the structure of which has been elucidated by X-ray analysis. The crystals are monoclinic P 2 1 / c with a = 10.640(2), b = 17.741(4), c = 17.845 (4) A, β = 90.50(3)°, Z = 4. The molecule has a CoCo bond and the {PhC 2 C(O)CH 3 } 3 chain links the cobalt atoms in a “flyover” arrangement. To our knowledge, this is the first example of stepwise formation of a symmetrical benzene from an asymmetrical, internal alkyne via this type of intermediate.

The rate of CO uptake in the reaction of HCo(CO) 4 with ethyloxirane, which gives (3-hydroxypentanoyl)cobalt tetracarbonyl as the major product in an n-octane/methyl isobutyl ketone solvent mixture at 15° C, is first order with respect to HCo(CO) 4 and ethyloxirane, and independent of the concentration of CO(CO) 4 − 4 or CO. The reaction is faster with DCo(CO) 4 . A preequilibrium ion pair formation and a subsequent rate-determining internal substitution, followed by fast CO insertion, accounts for these results.

Solutions of several iron(II) thiolato complexes in methanol, dimethylformamide or 2-ethoxyethanol reversibly absorb and release carbon monoxide at atmospheric pressure and 20–50 °C. Solutions of Fe(SPh) 2 (H 2 NCH 2 CH 2 NH 2 ) (CO) 2 and of an anionic complex tentatively formulated as [Fe 2 (SPh) 5 (CO) 4 ] − in 2-ethoxyethanol and of Fe(L-SCH 2 CH(NH 2 )COOEt) 2 (CO) 2 in dimethylformamide were found to be most effective for the separation of CONe 2 gas mixtures.

The (alkoxycarbonyl)cobalt tetracarbonyl BuOC(O)Co(CO)4 (I) was treated with the ligands ER3 (E = P, As, Sb; R = alkyl, aryl, alkoxy, dialkylamino) to give 37 monosubstituted products BuOC(O)Co(CO)3(ER3). Disubstituted derivs. contg. PR3 (R = Et, OMe) ligands were also made from I. The IR spectra of the compds. contg. various PR3 ligands were correlated with the electronic and steric parameters of the P-ligands. The crystal structure of BuOC(O)Co(CO)3PPh3 was detd. by x-ray crystallog.

The rate of CO uptake in the reaction of HCo(CO) 4 with ethyloxirane, which gives (3-hydroxypentanoyl)cobalt tetracarbonyl as the major product in an n-octane/methyl isobutyl ketone solvent mixture at 15° C, is first order with respect to HCo(CO) 4 and ethyloxirane, and independent of the concentration of CO(CO) 4 − 4 or CO. The reaction is faster with DCo(CO) 4 . A preequilibrium ion pair formation and a subsequent rate-determining internal substitution, followed by fast CO insertion, accounts for these results.

Complexes of the type PhSCo(CO) 2 L 2 ( 1 ; L = phosphine or phosphite) and the complex MeOCS 2 Co(CO) 2 (PPh 2 i Bu) 2 ( 5 ) have been prepared from CoCl 2 · 6H 2 O, CO, the appropriate phosphine or phosphite, and PhSH + NaOMe or MeOCS 2 K, respectively. The crystal structures of 1a (L = PPh 2 OMe) and 5 · MeCN have been determined. These compounds are the first structurally characterized cobalt carbonyl complexes containing a monodentate thiolate or xanthate group.

The «one-pot» combined hydrocarbalkoxylation-Michael addition reaction offers a relatively simple synthetic tool to prepare polyfunctionalized compounds from common starting materials. Furthermore, our results gave a new example for the control of homogeneous catalytic systems by basic additives

Phthalimidomethyl and phenoxymethyl as well as corresponding acetyl cobalt tetracarbonyls (1-4) were prepared and characterized. The single-crystal X-ray diffraction molecular structure of 1 (the first X-ray structure of an alkylcobalt tetracarbonyl with a pure organic alkyl group) was determined. The equilibrium constants of the equilibria 1 half arrow pointing right over half arrow pointing left 2 and 3 half arrow pointing right over half arrow pointing left 4 were determined at 20-60 and 20-40 degrees C, respectively

The neoadjuvant chemotherapy is increasingly being used in the treatment of patients with locally advanced breast cancer. We describe the hypothesis of the biological behaviour of breast cancer supporting the reason for the existence of this treatment. The improvement of neoadjuvant chemotherapy is being discussed as well as the advantages, disadvantages and problems of the treatment. THE AIM OF EXAMINATION: To study the results of neoadjuvant chemotherapy in patients with locally advanced breast cancer and the proportion of breast preserving surgery after the treatment.Sixty seven patients were given neoadjuvant chemotherapy treatment between 01.01.1999 and 12.31.2003. Twenty three patients were stage III A while 35 stage III B and 9 stage III C. 63% of the patients received CEF chemotherapy and 19% were given MMM. 18% were given neoadjuvant Taxotere + Carboplatin and 4% were given Taxotere + Farmorubicin chemotherapy.After neoadjuvant chemotherapy 5 patients had SD (stable disease), 32 patients had MR (minor response) and in 28 cases patients had PR (partial response). Two patients showed pCR (complete pathologic response). Twenty patients (30%) had breast preserving surgery.On the basis of our own experience neoadjuvant therapy is justified in patients with locally advanced breast cancer as they have bigger chance for breast preserving surgery. If mastectomy and axillary block dissection has to be carried out they are easier to perform. Taxans must be introduced for neoadjuvant treatment in order to improve our results. A longer follow-up is necessary before drawing final conclusions.

The equilibrium between acetylcobalt tetracarbonyl on one side and methylcobalt tetracarbonyl and carbon monoxide on the other has been determined in the 0–100°C temperature range. The decarbonylation of acetylcobalt tetracarbonyl is endothermic (Δ H = 11.2±0.6 Kcal mol −1 ) and is accompanied by a positive entropy change (Δ S = 19.5±2.0 e.u.).

The authors report on a rare manifestation of soft tissue metastasis of operated colorectal cancer. Interestingly, two years after the resection a etastasis with extremely high tumor marker level (CEA, CA 19.9) was detected. Marker elevation preceded the manifestation of metastasis by nearly half a year. After the metastasectomy the disease progressed. The authors briefly refer to the epidemiology of colorectal cancer, the complex therapy and the follow up.

The nickel complexes of Schiff bases formed fromo-aminothiophenol and α-dicarbonyl compounds, Ni(o-SC6H4N=CRCR=NC6H4S-o) (R=H, Me, Ph) (1a-c), catalyse the reduction of aromatic nitro compounds by NaBH4. The reduced species [Ni(o-SC6H4N=CHCH=NC6H4S-o)]− (2) and [Ni(o-SC6H4NHCH2CH=NC6H4S-o)]− (3) were identified as intermediates in the catalytic cycle.

Mono- and disubstitution of HCo(CO)4 with tertiary phosphines and phosphites was studied by IR and1H-NMR spectroscopy. It was found that these substitutions proceed through phosphonium tetracarbonylcobaltate intermediates, leading to a mixture of isomers. The crystal and molecular structure of trans-HCo(CO)3[P(O-p-C6H4Ph)3] was determined by X-ray diffraction.

Solutions of Fe(II) and thiolates (RS-: Fe2+ > 2; R = alkyl, phenyl) absorb carbon monoxide and - depending on the reaction conditions - several different anionic iron carbonyl derivatives are formed. Two of these complexes, fac-[Na(15-crown-5)][Fe(CO)3(SPh)3] (1) and fac-[K(18-crown-6)][Fe(CO)3(SPh)3] (2) were isolated and their crystal structures determined. (1) Crystallizes in the triclinic space group P1 with a = 11.915(3)A, b = 12.391(3)A, c = 14.337(3)A, α = 65.77(5), β = 116.28(5)°, γ = 105.87(5)°, V = 1720(1)A3, Z = 2, dcalcd = 1.30 gcm−3; (2) crystallizes in the cubic space group Pa3, with a = 19.609(4)A, V = 7540(3)A3, Z = 8, dcalcd = 1.4 gcm−3. Final agreement factors were R = 0.092, Rw = 0.102 (3919 reflections with F>7σ(F)) for (1); and R = 0.069, Rw = 0.050 (1125 reflections with F>4σ(F)) for (2). Both [Fe(CO)3(SPh)3]− anions of 1 and 2 have the same octahedral ligand arrangement with the carbonyl ligands cis to each other and trans with respect to the thiolato ligands. In complex 2 the K+ lies on the crystallographic threefold axis and is therefore exactly equidistant (3.475(2)A) from the three sulphur atoms; on the contrary in complex 1 in the Na+ is nearer to two of the three sulphur atoms (3.083(6)A and 3.334(6)A for the two different Na…S distances). The infrared spectra of the compounds were recorded in a variety of solvents and in the solid state. The Raman of crystalline 2 was also recorded. The failure of the vibrational spectra of crystalline 2 to follow either molecular point group or factor group predictions is explained in terms of an effective vibrational unit - and so, effective factor group - similar to that implicit in a factor group analysis of 1.

The «one-pot» combined hydrocarbalkoxylation-Michael addition reaction offers a relatively simple synthetic tool to prepare polyfunctionalized compounds from common starting materials. Furthermore, our results gave a new example for the control of homogeneous catalytic systems by basic additives

Several carbonyl derivatives of iron(II) thiolates containing N-donor ligands with the general formula FeS2N2(CO)2 were prepared in methanol solution starting from FeSO4·7H2O, the appropriate thiol (S) and nitrogen-donor ligand (N), carbon monoxide and a base. The structures of two representatives Fe(SC6H4- NH2-o)2(CO)2 (1) and Fe(SPh)2(H2NC2H4NH2)- (CO)2 (2) were determined. Complex 1 crystallizes with one molecule of THF in the triclinic space group P1, a=5.659(3), b=8.960(6), c=10.624(6) A, α= 105.15(5), β=103.23(5), γ=94.35(5)°, V=500.86 A3, Z=1, Dcalc=1.43 g cm−3. Complex 2 crystallizes in the monoclinic space group P21/c, a=11.739(2), b=9.725(2), c=15.868(2) A, β=101.583(8)°, V= 1774.6 A3, Z=4, Dcalc=1.44 g cm−3. Final agreement factors, R=0.0300, Rw=0.0304 (1787 reflections) for 1; R=0.0368, Rw=0.0369 (2147 reflections) for 2; the absolute configuration of 1 was determined. The octahedral complexes contain the two CO ligands in cis position and the coordinated N atoms are trans to the CO groups. A necessary condition for the stability of such complexes is the presence of at least one chelating ligand; all complexes lose CO on heating and this reaction is (in part) reversible.

Rhodium-phosphine complexes formed in situ from bis(1,5-hexadienechlororhodium), tertiary phosphines, and amines, catalyse the hydrodehalogenation of alkyl and aryl halides. Catalysts containing PPh 3 and with a P/Rh ratio of 1.1/1 are the most active; water increases the rate of the reaction.

The activity of catalysts for acetone hydrogenation formed in situ from [Rh(norbornadiene)Cl]2 and phosphines or phosphinic acid esters is determined by the electronic and steric effects of the ligand. The electronic parameter used was the infrared νco value of Rh(PR3)2(CO)Cl complexes containing the same P(III)-ligands. Catalytic activity increases with decreasing νco (i.e., increasing basicity of the ligand) and reaches its highest level with PEt3. Phosphines with larger, or branched, alkyl groups show still lower νco values but yield catalysts of lower, or even zero, activity because of the steric effects of the bulky ligands.

The “lactone” complexes, (C4O2R1,R2)Co2(CO)7, [μ2-carbonyl)[μ2-spiro-(2,3-substituted-2-butene-4-olide-4-ylidene)] [bis(tricarbonyl-cobalt)(CoCo) derivatives, were found to react with acetylenes (R3C2R4. This reaction yields the known acetylene complexes (R3C2R4Co2(CO)6 and two isomeric compounds with the composition [(C4O2R1,R2)(R3C2R4)2]Co2(CO)5. Spectroscopic arguments and X-ray structure determination show that both isomers contain σ, π-C5 ligands bonded to both Co atoms. The structures of these isomerswere identified.

Tetrabenzyltitanium and its dicyclohexylamine adduct react with carbon monoxide to form acylbenzyltitanium compounds, which have been characterized. The presence of (PhCH 2 ) 4 Ti(CO) 2 (amine) and (PhCH 2 ) 4 Ti(CO) (amine) as intermediates was indicated by the IR spectra.