Olefin Ligands Research Articles

Highly Reactive Cyclopentadienylcobalt(I) Olefin Complexes

The reduction of cobaltocene with metallic potassium in the presence of trimethylvinylsilane yielded the new CpCo(I) complex [CpCo(H2C═CHSiMe3)2] (6). Complex 6 turned out to be an ideal starting material for substitution reactions with functionalized mono- and diolefins, giving access to either new [CpCo(olefin)2] complexes such as 7 (trichlorovinylsilane) and 12 (dimethyl fumarate) or CpCo(diolefin) complexes such as 8 (diallyl ether), 9 (1,5-hexadiene), 10 (1,4-pentadiene), and 11 (1,1,3,3-tetramethyldivinyldisiloxane) with essentially quantitative yields. These complexes are rarely accessible by other methods or the direct reduction method using alkali metals. The complexes 6−9 were unambiguously characterized by X-ray structure analysis, which is reported for the first time for these types of complexes, giving way for the structural comparison. Computational calculations on the olefin ligand exchange processes with 6 display the different stabilities and reactivity trends of the different CpCo(I)-ole...

Exploring Rhodium-Catalysed Conjugate Addition of Chiral Alkenylboronates Using Chiral Olefin Ligands

The rhodium-catalysed addition of chiral alkenylboron reagents to prochiral α,β-unsaturated carbonyl acceptors are demonstrated to proceed under ligand control. The highest activities were obtained with chiral olefin ligands and the configuration of the new stereocentre can be predicted by using established models.

Phosphine–Alkene Ligands as Mechanistic Probes in the Pauson–Khand Reaction

An alkyne tetracarbonyl dicobalt complex with a chelated phosphine-alkene ligand, in which the phosphorus atom and the alkene from the ligand are attached to the same cobalt atom has been prepared, isolated, and characterized by X-ray crystallography. The complex serves as a mechanistic model for an intermediate of the Pauson-Khand (PK) reaction. Although the alkene fragment is located in an equatorial coordination site with an appropriate orientation, and, therefore, should undergo insertion, it failed to give the PK product upon either thermal or N-methylmorpholine N-oxide activation. However, a phosphine-alkene complex that contains a terminal alkene readily provided the corresponding PK product. We attribute this change in reactivity to the different ability of each olefin to undergo 1,2-insertion. These results provide further insights into the factors that govern a crucial step in the PK reaction, the olefin insertion.

Copper(I) Cyanide Coordination Polymers Constructed from Bis(Pyrazole-1-yl)alkane Ligands: Observation of the Odd−Even Dependence in the Structures

The mixture of CuCl2·2H2O and K3[Fe(CN)6] reacts with a series of flexible bis(pyrazole-1-yl)alkane ligands, Pz-(CH2)n-Pz (n = 1 for bpzm, n = 2 for bpze, n = 3 for bpzp, and n = 4 for bpzb), under hydrothermal conditions to produce four new copper(I) cyanide complexes: {[Cu2(CN)2(bpzm)]}n (1), {[Cu2(CN)2(bpze)]}n (2), {[Cu2(CN)2(bpzp)]}n (3), and {[Cu(CN)(bpzb)]}n (4), respectively. The X-ray analyses reveal that 1 exhibits a novel three-dimensional (3D) honeycomb-like framework, 2 shows a 2-fold interpenetration two-dimensional (2D) network, 3 exhibits a 3D structure, and 4 forms a 2D grid-like structure. An interesting odd−even phenomenon is observed in the complexes: when n is odd (n is the number of the CH2 spacer of ligands), the resulting complex exhibits a 3D framework, whereas when n is even, a 2D structure is generated. It could be explained that the numbers have a close relationship with dihedral angles among pyrazole rings of the ligands which have a great effect on the structures. Luminescent properties of the four complexes have been investigated in the solid state and 1 and 3 exhibit strong emissions, while 2 and 4 generate weak or no emission.

Binding energy of d10 transition metals to alkenes by wave function theory and density functional theory☆

Abstract The structures of Pd(PH 3 ) 2 and Pt(PH 3 ) 2 complexes with ethene and conjugated C n H n + 2 systems ( n = 4, 6, 8, and 10) were studied. Their binding energies were calculated using both wave function theory (WFT) and density functional theory (DFT). Previously it was reported that the binding energy of the alkene to the transition metal does not depend strongly on the size of the conjugated C n H n + 2 ligand, but that DFT methods systematically underestimate the binding energy more and more significantly as the size of the conjugated system is increased. Our results show that recently developed density functionals predict the binding energy for these systems much more accurately. New benchmark calculations carried out by the coupled cluster method based on Brueckner orbitals with double excitations and a quasiperturbative treatment of connected triple excitations (BCCD(T)) with a very large basis set agree even better with the DFT predictions than do the previous best estimates. The mean unsigned error in absolute and relative binding energies of the alkene ligands to Pd(PH 3 ) 2 is 2.5 kcal/mol for the ωB97 and M06 density functionals and 2.9 kcal/mol for the M06-L functional. Adding molecular mechanical damped dispersion yields even smaller mean unsigned errors: 1.3 kcal/mol for the M06-D functional, 1.5 kcal/mol for M06-L-D, and 1.8 kcal/mol for B97-D and ωB97X-D. The new functionals also lead to improved accuracy for the analogous Pt complexes. These results show that recently developed density functionals may be very useful for studying catalytic systems involving Pd d 10 centers and alkenes.

Rhodium/olefin-catalyzed reaction of arylboronic acids with an α-acetamido acrylic ester: Mizoroki–Heck-type reaction versus asymmetric conjugate addition

In this paper we present our results concerning the rhodium/olefin-catalyzed reaction of arylboronic acids with an α-acetamido acrylic ester. With a chiral norbornadiene ligand rather low enantioselectivities (up to 21% ee) were obtained. Besides the expected conjugate adduct, we also observed the formation of a significant amount of Mizoroki–Heck-type product. The ratio of the conjugate adduct/Mizoroki–Heck product could be adjusted by a proper choice of the olefin ligand.

Dicationic Alkylidene−, Olefin−, and Alkoxyalkenylcarbene−Osmium Complexes Stabilized by a NHC Ligand

Complex [Os(═CHPh)(CH3CN)4(IPr)](OTf)2 (1) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazolylidene; OTf = CF3SO3) exchanges the alkylidene group with propylene to give styrene and [Os(═CHCH3)(CH3CN)4(IPr)](OTf)2 (2). The reaction of 1 with ethylene leads to [Os(η2-CH2═CH2)(CH3CN)4(IPr)](OTf)2 (3) via the propylene intermediate [Os(η2-CH2═CHCH3)(CH3CN)4(IPr)](OTf)2 (4). Acetonitrile displaces the olefin ligand of both 3 and 4 to generate the pentakis(solvento) derivative [Os(CH3CN)5(IPr)](OTf)2 (5). In 2-propanol and methanol, complex 5 reacts with 1,1-diphenyl-2-propyn-1-ol and 2-methyl-3-butyn-2-ol to yield the corresponding alkoxyalkenylcarbene compounds [Os{═C(OR)CH═CR′2}(CH3CN)4(IPr)](OTf)2 (R = CH(CH3)2; R′ = Ph (6), CH3 (7); R = CH3; R′ = Ph (8), CH3 (9)). The X-ray structures of 4, 5, and 6 are also reported.

Fundamental aspects of nucleation and growth in the solution-phase synthesis of germanium nanocrystals

Colloidal Ge nanocrystals (NCs) were synthesized via the solution phase reduction of germanium(II) iodide. We report a systematic investigation of the nanocrystal nucleation and growth as a function of synthesis conditions including the nature of coordinating solvents, surface bound ligands, synthesis duration and temperature. NC synthesis in reaction environments with weakly bound phosphine surface ligand led to the coalescence of nascent particles leading to ensembles with broad lognormal particle diameter distributions. Synthesis in the presence of amine or alkene ligands mitigated particle coalescence. High-resolution transmission electron micrographs revealed that NCs grown in the presence of weak ligands had a high crystal defect density whereas NCs grown in amine solutions were predominantly defect-free. We applied infrared spectroscopy to study the NC surface chemistry and showed that alkene ligands project the NCs from surface oxidation. Photoluminescence spectroscopy measurements showed that alkene ligands passivate surface traps, as indicated by infrared fluorescence, conversely oxidized phosphine and amine passivated NCs did not fluoresce.

Facile Double C−H Activation of Tetrahydrofuran by an Iridium PNP Pincer Complex

The reaction of [IrCl(COE)2]2 (COE = cyclooctene) with bulky PNP amino pincer ligand HN(CH2CH2PtBu2)2, (HPNP)tBu, results in high-yield formation of iridium(III) complex [IrH(C8H13)Cl(HPNP)tBu] after oxidative addition of a vinylic COE C−H bond. Upon dissolving the product in polar solvents or chloride abstraction with TlPF6 the cationic iridium(I) complex [Ir(COE)(HPNP)tBu]+ is obtained, which is thermally unstable. This observation shows that the olefin isomer represents the thermodynamic minimum for the cationic complex, while the cyclooctenyl hydride isomer is trapped in nonpolar solvents by anion coordination. Owing to the lability of the olefin ligand, [Ir(COE)(HPNP)tBu]+ undergoes facile intermolecular C−H activation. Fischer-carbene complex [Ir(H)2(═CO(CH2)3)(HPNP)tBu]BPh4 was isolated in good yield upon α,α-dehydrogenation of THF. Mechanistic examinations suggest olefin dissociation to be rate-determining.

Chemically Linked AuNP−Alkane Network for Enhanced Photoemission and Field Emission

Size and ligand effects are the basis for the novel properties and applications of metallic nanoparticles (NPs) in nanoelectronics, optoelectronics, and biotechnology. This work reports the first observation of enhanced photoelectron emission from metallic Au NPs ligated by alkanethiols. The enhancement is based on a conceptually new mechanism: the AuNP provides electrons while the alkane ligand emits electrons due to its low or negative electron affinity. Moreover, the AuNP-ligand chemical bonding is found to significantly facilitate the transmission of photoexcited electrons from the AuNP to the ligand emitter. Consequently the smooth NP film, which is a typical low-aspect-ratio two-dimensional structure, exhibits strong and stable field emission behavior under photoillumination conditions. The photoenhanced field emission is related to the interband and surface plasmon transitions in AuNPs, and a photoenhancement factor of up to approximately 300 is observed for the AuNP-based field emission. This is highly remarkable because field emission is often based on one-dimensional, high-aspect-ratio nanostructures (e.g., nanotubes and nanowires) with geometrical field enhancement effect. The chemical linkage of electron-supplying AuNP and electron-emitting alkane ligand represents a fundamentally new mechanism for efficient photoexcitation and emission. Being low-temperature/solution processable, and inkjet printable, AuNPs may be a flexible material system for optoelectronic applications such as photodetection and photoenhanced field emission.

Synthesis and characterization of novel homo- and heterobimetallic palladium(0) and platinum(0) complexes of olefinic bismacrocyclic ligands

Synthesis and characterization of novel homo- and heterobimetallic palladium(0) and platinum(0) complexes of olefinic bismacrocyclic ligands

Stereochemical Control by an Ester Group or Olefin Ligand in Platinum‐Catalyzed Carboalkoxylation of 6‐(1‐Alkoxyethoxy)‐ hex‐2‐ynoates

Abstractmagnified imageThe cyclization of 6‐(1‐alkoxyethoxy)hex‐2‐ynoantes in the presence of the platinum‐olefin catalyst system gave the corresponding multisubstituted 2‐[dihydrofuran‐2(3H)‐ylidene]acetates in good to high yields. The Z/E selectivity is controlled by the electronic property of the ester group; the 2,2,2‐trichloroethyl ester yielded the Z isomer, while the phenyl ester gave the E isomer. Moreover, we found that the Z/E selectivities in the reaction of phenyl esters 1h, 1n, and 1o were controlled by the olefin ligand. For example, the platinum‐catalyzed reaction of 1h using 1,5‐hexadiene as the olefin ligand gave E‐2h as the major product, while that using 1,5‐cyclooctadiene produced mainly the Z isomer.

Sterically Encumbered Iridium Bis(N-heterocyclic carbene) Systems: Multiple C−H Activation Processes and Isomeric Normal/Abnormal Carbene Complexes

The reaction of [Ir(coe)2Cl]2 (coe = cyclooctene) with the N-heterocyclic carbene N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr) in tetrahydrofuran under anaerobic conditions leads to the formation of two main products, the planar four-coordinate Ir(I) complex Ir(IPr)(IPr′′)Cl (1) formed by dehydrogenation of one of the IPr isopropyl substituents (to give the mixed NHC/alkene donor IPr′′) and the trigonal bipyramidal Ir(III) system Ir(IPr)(aIPr)(H)2Cl (6), which features both “normal” and “abnormal” C-bound isomers of the NHC ligand. Formation of 1 presumably proceeds via initial C−H activation at iridium(I); moreover, subsequent reactivity for 1 initiated by chloride abstraction suggests that C−H oxidative addition chemistry is facile for the methyl C−H bonds of the carbene isopropyl substituent. Thus, the square pyramidal Ir(III) alkene alkyl hydride [Ir(IPr′)(IPr”)H]+[BArf4]− (2) is formed on reaction with Na[BArf4] in fluorobenzene. In contrast to the Ir(I) system 1, the alignment of the alkene ligand in solid 2 is such that it lies coplanar with the IrC4 basal plane. Quantum chemical investigations imply that the energetic difference between this alkene orientation and an alternative perpendicular conformation is small (ca. 5 kcal mol−1), with steric factors (notably at the alkene 2-position) being important. Hydrogenation of 1 proceeds via an intermediate identified as Ir(IPr)(IPr′′)(H)2Cl to give the Ir(III) dihydride Ir(IPr)2(H)2Cl (4), the structure of which can be compared with those of the tautomeric isomer 6 and the mixed IPr/IMes carbene complex Ir(IPr)(IMes)(H)2Cl [IMes = N,N′-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene]. Crystallographically determined bond lengths for the Ir−C linkages trans to the respective carbenes imply relatively similar σ-donor properties for the IPr, aIPr, and IMes ligands.

Acceleration of Reductive Elimination of [Ar‐Pd‐C] by a Phosphine/Electron‐Deficient Olefin Ligand: A Kinetic Investigation

The kinetics of the reductive elimination step of a C(sp(3))-C(sp(2)) Negishi cross-coupling catalyzed by a 1:1 complex 2 of palladium and the phosphine/electron-deficient olefin ligand (E)-3-(2-diphenylphosphanylphenyl)-1-phenyl-propenone (1) was studied. Complex 2 is an exceptionally efficient and highly selective catalyst for Negishi cross-coupling reactions involving primary and secondary alkylzinc reagents bearing beta-hydrogen atoms. Turnover numbers (TONs) as high as 10(5) and turnover frequencies (TOFs) as high as 1000 s(-1) were observed. The reactions occurred rapidly and selectively even at 0 degrees C. The fact that the reaction was first order in [Pd] is consistent with homogeneous catalysis by Pd complexes rather than by Pd nanoparticles (NPs). Through systematic kinetic investigations of the Negishi coupling of ethyl 2-iodobenzoate with alkylzinc chlorides, the rate constants for reductive elimination of [Ar-Pd-C(sp(3))] were determined to be >0.3 s(-1), which is about 4 or 5 orders of magnitude greater than the values previously reported for [Pd(dppbz)] and [Pd(PPh(3))(2)] systems (dppbz = 1,2-bis(diphenylphosphino)benzene). The use of a 2:1 ratio of 1:Pd resulted in reduced catalytic activity and selectivity, presumably because the olefin moiety could no longer assist in the reductive elimination step. Importantly, hydrogenation of the C=C double bond in ligand 1 generated a saturated ligand (1H(2)), which was not only less effective than 1, but also gave rise to substantial amount of ethylbenzoate formed by competing beta-hydride elimination. Thus, the pi-accepting olefin moiety in 1 must enhance reductive elimination rates, and, consequently, inhibit formation of byproducts resulting from beta-hydride elimination.

Alkyl dehydrogenation in iridium tri-cyclopentyl phosphines

The iridium cyclooctadiene complex incorporating a tricyclopentyl phosphine ligand (PCyp 3), Ir(η 2:η 2-C 8H 12)(PCyp 3)Cl, has been prepared. Removal of the chloride from this complex using Na [ BAr F 4 ] [ Ar F = C 6 H 3 ( CF 3 ) 2 ] in CH 2Cl 2/arene solvent results in dehydrogenation (C–H activation followed by β-H transfer) of one of the alkyl phosphine rings and formation of the complexes [ Ir ( η 6 - C 6 H 5 X ) { PCyp 2 ( η 2 - C 5 H 7 ) } ] [ BAr F 4 ] (X = H, F) which contain a hybrid phosphine–alkene ligand. These complexes are formed alongside another product (5–20% yield) that has been identified as [ Ir ( η 2 : η 2 - C 8 H 12 ) { PCyp 2 ( η 2 - C 5 H 7 ) } ] [ BAr F 4 ] , which can be prepared in high yield by an alternative, and slightly modified, route. This complex is with a minor isomer that has been tentatively identified as [ Ir ( η 2 : η 3 - C 8 H 11 ) ( H ) { PCyp 2 ( η 2 - C 5 H 7 ) } ] [ BAr F 4 ] , which results from allylic C–H activation of cyclooctadiene. Addition of H 2 to [ Ir ( η 2 : η 2 - C 8 H 12 ) { PCyp 2 ( η 2 - C 5 H 7 ) } ] [ BAr F 4 ] and its isomer in arene solvent (C 6H 5X, X = F, H) forms the dihydrido η 6-arene Ir(III) complexes [ Ir ( H ) 2 ( η 6 - C 6 H 5 X ) ( PCyp 3 ) ] [ BAr F 4 ] . In contrast, hydrogenation in CH 2Cl 2 alone results in the formation of Ir ( H ) 2 ( PCyp 3 ) { η 6 - ( C 6 H 3 ( CF 3 ) 2 ) BAr F 3 } in which the [ BAr F 4 ] - anion is now acting as a ligand through one of its aryl rings. The fluorobenzene complex [ Ir ( H ) 2 ( η 6 - C 6 H 5 F ) ( PCyp 3 ) ] [ BAr F 4 ] can be cleanly converted to [ Ir ( η 6 - C 6 H 5 F ) { PCyp 2 ( η 2 - C 5 H 7 ) } ] [ BAr F 4 ] by addition of the hydrogen acceptor tert-butylethene (tbe).

Ruthenium Polypyridyl Complexes Containing a Conjugated Ligand LDQ (LDQ = 1-[4-(4′-methyl)-2,2′-bipyridyl]-2-[4-(4′-N,N′-tetramethylene-2,2′-bipyridinum)]ethene): Synthesis, Characterization, and Photoinduced Electron Transfer at Solution−Zeolite Interfaces

Photoinduced electron transfer from sensitizers attached to zeolite surface to electron acceptors within the zeolite provides opportunities for long-lived charge separation, as well as potential utilization of the charge separated species. In this study, the focus is on the ruthenium polypyridyl compound [(bpy)2RuLDQ]4+ (where bpy = bipyridine, and LDQ = 1-[4-(4′-methyl)-2,2′-bipyridyl]-2-[4-(4′-N,N′-tetramethylene-2,2′-bipyridinium)]ethene) and its unquaternized analogue of structural formula [(bpy)2RuL]2+ (L = trans-1,2-bis[4-(4′-methyl)-2,2′-bipyridyl]ethene). Both complexes show strong metal-to-ligand charge-transfer (MLCT) and olefinic ligand based absorption bands. The emission of [(bpy)2RuLDQ]4+ in solution is quenched, whereas the [(bpy)2RuL]2+ complex exhibits emission at 675 nm. The quenching is attributed to the intramolecular electron transfer from the Ru center to the diquat (DQ) moiety upon photoexcitation. The [(bpy)2RuLDQ]4+ complex is stable upon visible light illumination, while [(bpy)2R...

Transferring the Concept of Multinuclearity to Ruthenium Complexes for Improvement of Anticancer Activity

Multinuclear platinum anticancer complexes are a proven option to overcome resistance of established anticancer compounds. Transferring this concept to ruthenium complexes led to the synthesis of dinuclear Ru(II)-arene compounds containing a bis(pyridinone)alkane ligand linker. A pronounced influence of the spacer length on the in vitro anticancer activity was found, which is correlated to the lipophilicity of the complexes. IC(50) values in the same dimension as for established platinum drugs were found in human tumor cell lines. No cross-resistance to oxoplatin, a cisplatin prodrug, was observed for the most active complex in three resistant cell lines; in fact, a 10-fold reversal of sensitivity in two of the oxoplatin-resistant lines was found. (Bio)analytical characterization of the representative examples showed that the ruthenium complexes hydrolyze rapidly, forming predominantly diaqua species that exhibit affinity toward transferrin and DNA, indicating that both proteins and nucleobases are potential targets.

Synthesis, Crystal Structures, and Photoluminescent Properties of the Cu(I)/X/α,ω-Bis(benzotriazole)alkane Hybrid Family (X = Cl, Br, I, and CN)

This work focused on a systematic investigation of the influences of the spacer length of the flexible alpha,omega-bis(benzotriazole)alkane ligands and counteranions on the overall molecular architectures of hybrid structures that include Cu(I). Using the self-assembly of CuX (X = Cl, Br, I, or CN) with the five structurally related flexible organic ligands (L1-L5) under hydro(solvo)thermal conditions, we have synthesized and characterized 10 structurally unique materials of the Cu(I)/X/alpha,omega-bis(benzotriazole)alkane organic-inorganic hybrid family, {[CuCl](2)(L1)}(n) (1), {[CuBr](L2)}(n) (2), {[CuCl](2)(L3)}(n) (3), {[CuI](2)(L4)}(n) (4), {[CuBr](2)(L4)}(n) (5), {[CuBr](3)(L5)}(n) (6), {[CuCN](2)(L1)}(n) (7), {[CuCl](4)(L2)}(n) (8), {[CuBr](4)(L2)}(n) (9), and {[CuCl](2)(L4)}(n) (10), by means of elemental analyses, X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, and photoluminescence measurements. Single-crystal X-ray analyses showed that the inorganic subunits in these compounds were {Cu(2)X(2)} binuclear clusters (1 and 2), {Cu(4)X(4)} cubane clusters (4, 5, and 10), {CuX}(n) single chains (3 and 7), a {Cu(3)X(3)}(n) ladderlike chain (6), and unprecedented {Cu(8)X(8)}(n) ribbons (8 and 9). The increasing dimensionality from 1-D (1-4) to 2-D (5 and 6) to 3-D (7-10) indicates that the spacer length and isomerism of the bis(benzotriazole)alkane ligands play an essential role in the formation of the framework of the Cu(I) hybrid materials. The influence of counteranions and pi-pi stacking interactions on the formation and dimensionality of these hybrid coordination polymers has also been explored. In addition, all the complexes exhibit high thermal stability and strong fluorescence properties in the solid state at ambient temperature.

Ion-tagged π-acidic alkene ligands promote Pd-catalysed allyl–aryl couplings in an ionic liquid

Ionic pi-acidic alkene ligands based on chalcone and benzylidene acetone frameworks have been "doped" into ionic liquids to provide functional reaction media for Pd-catalysed cross-couplings of a cyclohexenyl carbonate with aryl siloxanes that allow simple product isolation, free from Pd (<50 ppm) and ligand contamination.

Redox Activation of Alkene Ligands in Platinum Complexes with Non-innocent Ligands

The reactivity of metal olefin complexes with non-innocent ligands (NILs) was examined. Treatment of PtCl(2)(diene) with the deprotonated catechol or aminophenol ligands afforded the corresponding Pt(NIL)(diene) complexes. The Pt((t)BA(F)Ph)(COD), Pt((t)BA(F)Ph)(nbd), and Pt(O(2)C(6)H(2)(t)Bu(2))(COD) (H(2)(t)BA(F)Ph = 2-(2-trifluoromethyl)anilino-4,6-di-tert-butylphenol, H(2)O(2)C(6)H(2)(t)Bu(2) = 3,5-di-tert-butylcatechol) complexes were examined by cyclic voltammetry. Treatment of Pt((t)BA(F)Ph)(COD) or Pt((t)BA(F)Ph)(nbd) with AgPF(6) afforded the imino-semiquinones [Pt((t)BA(F)Ph)(COD)]PF(6) or [Pt((t)BA(F)Ph)(nbd)]PF(6), respectively. The [Pt((t)BA(F)Ph)(COD)] complex was unreactive toward nucleophiles, whereas the oxidized derivative, [Pt((t)BA(F)Ph)(COD)]PF(6), rapidly and stereospecifically added alkoxides at the carbon trans to the phenolate. The Pt((t)BA(F)Ph)(COD), [Pt((t)BA(F)Ph)(COD)]PF(6), Pt((t)BA(F)Ph)(C(8)H(12)OMe), and [Cp(2)Co][Pt((t)BA(F)Ph)(C(8)H(12)OMe)] complexes were characterized crystallographically.