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1.
Carlo Allasia Mario Castiglioni Roberto Giordano Enrico Sappa Francesco Verre 《Journal of Cluster Science》2000,11(4):493-509
The title complexes were tested in the hydrogenation of hex-3-yne and of 1,3- and 1,4-cyclohexadiene (CHD) under solid–gas conditions. The clusters were deposited on three “standard” supports, that is, pyrex glass, alumina, and silica. All the clusters, particularly (μ-H)Ru3(CO)10(PPh2), show hydrogenation activity. However, they are not particularly selective toward the formation of monoenes; “disproportionation” of 1,3- and 1,4-CHD to hydrogenated products and benzene also occurs. The hydrogenation activity of the clusters is dependent on their nature, the type of substrate, and the characteristics of the supporting material; silica and pyrex glass are usually more active than alumina. Attempts at detecting the formation of organometallic intermediates or by-products (through IR spectroscopy) were made. HRTEM was used to check for eventual decomposition on some supports. 相似文献
2.
V. V. Krivykh O. A. Kizas E. V. Vorontsov A. A. Koridze 《Russian Chemical Bulletin》1996,45(12):2840-2842
Triosmium cluster Os3(-H)(CO)10(--2-CCC Me2OMe) (1) was obtained by treating OS3(-H)(-Cl)(CO)10 with LiCCCMe2OMe. The reaction of cluster1 with HBF4 · Et2O at –60 °C leads to the cationic complex [Os3(-H)(CO)10(-,,2-C=C=C Me2)]+BF4
– (2) with an allenylidene ligand. Thes1H and13C NMR spectra of complex2 reveal the temperature dependence caused by migration of hydrocarbon and carbonyl ligands. Thermodynamic parameters were obtained for be exchange process of the allenylidene ligand.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp, 2990–2992, December, 1996. 相似文献
3.
《Journal of Coordination Chemistry》2012,65(3-4):199-210
Abstract The kinetics for isomerization of HRu3 (μ3-η3-EtSCCMeCMe)(CO)9 TO Ru3(μ-SEt) (μ3-η3-CCMeCHMe)(CO)9, were determined. The overall process involves C[sbnd]H elimination, C[sbnd]S and Ru[sbnd]Ru bond cleavage and Ru2(μ-S) bond formation. Activation parameters were determined from the temperature dependence (ΔH? = 127(3) kJ/mol, ΔS?= 56(11) J/mol-K) and from the pressure dependence (0[sbnd]207 MPa, ΔV? 0 +12.7(1.1) cm3/mol, Δβ? = +0.037(0.012) cm3/(mol-MPa)) of the rate constant. The data are consistent with an intramolecular reaction involving significant metal-metal or carbon-sulfur bond cleavage in the transition state. The activation volume is too large to be accommodated by C[sbnd]H elimination alone and CO dissociation is not involved. 相似文献
4.
A. A. Koridze Y. I. Zdanovich N. V. Andrievskaya Yu. Siromakhova P. V. Petrovskii M. G. Ezernitskaya F. M. Dolgushin A. I. Yanovsky Yu. T. Struchkov 《Russian Chemical Bulletin》1996,45(5):1200-1206
Diyne FcCmCC.CFc (Fc is ferrocenyl) reacts with Ru3(CO)12 in boiling hexane to yield binuclear complexes Ru2 and Ru2(CO)6(C4Fc2(C=CFc)2C=O) containing ruthenacyclopentadiene and diruthenacycloheptadienone rings, respectively. The isomerism of the complexes is due to the different ways of coupling of the alkyne fragments of the diyne, namely, head-to-head, head-to-tail or tail-to-tail. The reaction of enyne PhC=CCH=CHPh with Ru3(CO)12 under similar conditions gives isomeric binuclear complexes Ru2(CO)6(C4Ph2(CH=CHPh)2) and trinuclear clusters Ru3(CO)6(w-CO)2(C4Ph2(CH=CHPh)2) and Ru3(CO)8(3-,1-1-4-2 C4Ph2(CH=CHPh)2). The structure of the latter was determined by X-ray diffraction analysis. The Ru3 triangle coordinates eight terminal CO groups and the organic ligand resulting from the head-to-head dimerization of enyne molecules; the ruthenacyclopentadiene moiety is 4-coordinated to the Ru(CO)2 group, and the third ruthenium atom is 2-bound to one of the PhCH=CH groups.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1261–1267, May, 1996. 相似文献
5.
Noorjahan Begum Dennis W. Bennett G. M. Golzar Hossain Shariff E. Kabir Ayesha Sharmin Daniel T. Haworth Tasneem A. Siddiquee Edward Rosenberg 《Journal of Cluster Science》2005,16(3):413-428
Treatment of the electronically unsaturated 4-methylquinoline triosmium cluster $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu_3\hbox{-}\upeta^{2}\hbox{-}\hbox{C}_{9}\hbox{H}_{5} \hbox{(4-Me)N})(\upmu\hbox{-H})]$ (1) with tetramethylthiourea in refluxing cyclohexane at 81°C gave $[\hbox{Os}_{3}\hbox{(CO)}_{8}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5} \hbox{(4-Me)N})(\upeta^2\hbox{-SC}(\hbox{NMe}_2\hbox{NCH}_2\hbox{Me})(\upmu \hbox{-H})_2]$ (2) and $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5}\hbox{(4-Me)N})(\upeta^1\hbox{-SC}(\hbox{NMe}_2)_2)(\upmu\hbox{-H})]$ (3). In contrast, a similar reaction of the corresponding quinoline compound $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu_{3}\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N})(\upmu\hbox{-H})]$ (4) with tetramethylthiourea afforded $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu\hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N})(\upeta^{1}\hbox{-SC(NMe}_{2})_{2})(\upmu\hbox{-H)}]$ (5) as the only product. Compound 2 contains a cyclometallated tetramethylthiourea ligand which is chelating at the rear osmium atom and a quinolyl ligand coordinated to the Os3 triangle via the nitrogen lone pair and the C(8) atom of the carbocyclic ring. In 3 and 5, the tetramethylthiourea ligand is coordinated at an equatorial site of the osmium atom, which is also bound to the carbon atom of the quinolyl ligand. Compounds 3 and 5 react with PPh3 at room temperature to give the previously reported phosphine substituted products $[\hbox{Os}_{3}\hbox{(CO)}_{9}(\upmu \hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{5}\hbox{(4-Me)N)(PPh}_{3})(\upmu\hbox{-H)}]$ (6) and $[\hbox{Os}_{3}\hbox{(CO}_{9}(\upmu \hbox{-}\upeta^{2}\hbox{-C}_{9}\hbox{H}_{6}\hbox{N)(PPh}_{3})(\upmu\hbox{-H)}]$ (7) by the displacement of the tetramethylthiourea ligand. 相似文献
6.
《Journal of organometallic chemistry》1988,356(2):C61-C64
The reaction of Pt(C2H4)2(PCy3) with (OC)4M(μ-H)(μ-PnPr2)Pt(CO)(PCy3, (1: M Cr, Mo, W) occurs in a highly specific, kinetically controlled manner to give MPt2(μ2MPt-CO)(η2PtPt-H)(μ2MPt-PnPr2)(CO)4 (PCy3)2 (5), as the first formed trimer. The trimer 5 (M Mo, W) isomerizes to give MPt2(μ2PtPt-CO) ((μ2MPtH)(μ2MPt-PnPr2)(CO)4)PCy3)2 (6) which in turn isomerizes to MPt2μ2MPtCO)(μ2MPt (μ2PtPt-PnPr2)(CO)4(PCy3)2 (7, as the final isolable product. These results provide a detailed insight into the mechanism of “Pt(PCy3) addition”, a cluster assembly process. 相似文献
7.
Maksakov V. A. Slovohotova I. V. Golovin A. V. Babailov S. P. 《Russian Chemical Bulletin》2001,50(12):2451-2458
The reactions of the heterometallic complexes (-H)Os3(-O2CC5H4FeCp)(CO)10 (1) and Fe{(-O2CC5H4)(-H)Os3(CO)10}2 (2) with CF3COOH, CF3SO3H, and AcCl were studied. The reaction of 1 with CF3COOH involves interaction with the Cp ligands, protonation of the O atom of the bridging carboxylate group, and oxidative degradation of the complex. At low concentrations, CF3SO3H protonates the O atom of the bridging carboxylate group, while at high concentrations, degradation of the complex takes place. The reaction of complex 2with either CF3COOH or low concentrations of CF3SO3H results in successive elimination of two [(-H)Os3(CO)10] cluster fragments due to protonation of the O atoms of the carboxylate groups. In the case of high CF3SO3H concentrations, the Os—Os bonds of both cluster fragments of 2 are also protonated to give the [Fe{(-O2CC5H4)(-H)2Os3(CO)10}2]2+ dication. The Friedel—Crafts acylation of 1 takes place only when a large excess of AcCl and AlCl3 is used to give two new complexes, (-H)Os3(-O2CC5H4FeC5H4C(O)CH3)(CO)10 and (-H)Os3(-O2CC5H3C(O)CH3FeCp)(CO)10 in a 2 : 1 ratio. 相似文献
8.
The electron distributions and bonding in Ru3(CO)9(
3-
2,
2,
2-C6H6) and Ru3(CO)9(
3-
2,
2,
2-C60) are examined via electronic structure calculations in order to compare the nature of ligation of benzene and buckminsterfullerene to the common Ru3(CO)9 inorganic cluster. A fragment orbital approach, which is aided by the relatively high symmetry that these molecules possess, reveals important features of the electronic structures of these two systems. Reported crystal structures show that both benzene and C60 are geometrically distorted when bound to the metal cluster fragment, and our ab initio calculations indicate that the energies of these distortions are similar. The experimental Ru–Cfullerene bond lengths are shorter than the corresponding Ru–Cbenzene distances and the Ru–Ru bond lengths are longer in the fullerene-bound cluster than for the benzene-ligated cluster. Also, the carbonyl stretching frequencies are slightly higher for Ru3(CO)9(
3-
2,
2,
2-C60) than for Ru3(CO)9(
3-
2,
2,
2-C6H6). As a whole, these observations suggest that electron density is being pulled away from the metal centers and CO ligands to form stronger Ru–Cfullerene than Ru–Cbenzene bonds. Fenske-Hall molecular orbital calculations show that an important interaction is donation of electron density in the metal–metal bonds to empty orbitals of C60 and C6H6. Bonds to the metal cluster that result from this interaction are the second highest occupied orbitals of both systems. A larger amount of density is donated to C60 than to C6H6, thus accounting for the longer metal–metal bonds in the fullerene-bound cluster. The principal metal–arene bonding modes are the same in both systems, but the more band-like electronic structure of the fullerene (i.e., the greater number density of donor and acceptor orbitals in a given energy region) as compared to C6H6 permits a greater degree of electron flow and stronger bonding between the Ru3(CO)9 and C60 fragments. Of significance to the reduction chemistry of M3(CO)9(
3-
2,
2,
2-C60) molecules, the HOMO is largely localized on the metal–carbonyl fragment and the LUMO is largely localized on the C60 portion of the molecule. The localized C60 character of the LUMO is consistent with the similarity of the first two reductions of this class of molecules to the first two reductions of free C60. The set of orbitals above the LUMO shows partial delocalization (in an antibonding sense) to the metal fragment, thus accounting for the relative ease of the third reduction of this class of molecules compared to the third reduction of free C60. 相似文献
9.
Frank W. Vergeer Taasje Mahabiersing Enrique Lozano Diz Georg Süss-Fink František Hartl 《Journal of Cluster Science》2004,15(1):47-59
Electrochemical and photochemical properties of the tetrahedral cluster [Ru3Ir(
3-H)(CO)13] were studied in order to prove whether the previously established thermal conversion of this cluster into the hydrogenated derivative [Ru3Ir(-H)3(CO)12] also occurs by means of redox or photochemical activation. Two-electron reduction of [Ru3Ir(
3-H)(CO)13] results in the loss of CO and concomitant formation of the dianion [Ru3Ir(
3-H)(CO)12]2–. The latter reduction product is stable in CH2Cl2 at low temperatures but becomes partly protonated above 283K into the anion [Ru3Ir(-H)2(CO)12]– by traces of water. The dianion [Ru3Ir(
3-H)(CO)12]2– is also the product of the electrochemical reduction of [Ru3Ir(-H)3(CO)12] accompanied by the loss of H2. Stepwise deprotonation of [Ru3Ir(-H)3(CO)12] with Et4NOH yields [Ru3Ir(-H)2(CO)12]– and [Ru3Ir(
3-H)(CO)12]2–. Reverse protonation of the anionic clusters can be achieved, e.g., with trifluoromethylsulfonic acid. Thus, the electrochemical conversion of [Ru3Ir(
3-H)(CO)13] into [Ru3Ir(-H)3(CO)12] is feasible, demanding separate two-electron reduction and protonation steps. Irradiation into the visible absorption band of [Ru3Ir(
3-H)(CO)13] in hexane does not induce any significant photochemical conversion. Irradiation of this cluster in the presence of CO with
irr>340nm, however, triggers its efficient photofragmentation into reactive unsaturated ruthenium and iridium carbonyl fragments. These fragments are either stabilised by dissolved CO or undergo reclusterification to give homonuclear clusters. Most importantly, in H2-saturated hexane, [Ru3Ir(
3-H)(CO)13] converts selectively into the [Ru3Ir(-H)3(CO)12] photoproduct. This conversion is particularly efficient at
irr
>340nm. 相似文献
10.
The reaction of PtRu5(CO)16(μ6-C),1 with 3-hexyne in the presence of UV irradiation produced two new electron-rich platinum-ruthenium cluster complexes PtRu5(CO)13(μ-EtC2Et)(μ3-EtC2Et)(μ5-C),2 (20% yield) and Pt2Ru6(CO)17(μ-η5-Et4C5)(μ3-EtC2Et) (μ6-C),3 (7% yield). Both compounds were characterized by single-crystal X-ray diffraction analyses. Compound2 contains of a platinum capped square pyramidal cluster of five ruthenium atoms with the carbido ligand located in the center of the square pyramid. A EtC2Et ligand bridges one of the PtRu2 triangles and the Ru-Pt bond between the apical ruthenium atom and the platinum cap. The structure of compound3 consists of an octahedral PtRu5 cluster with an interstitial carbido ligand and a platinum atom capping one of the PtRu2 triangles. There is an additional Ru(CO)2 group extending from the platinum atom in the PtRu5 cluster that contains a metallated tetraethylcyclopentadienyl ligand that bridges to the platinum capping group. There is also a EtC2Et ligand bridging one of the PtRu2 triangular faces to the capping platinum atom. Compounds2 and3 both contain two valence electrons more than the number predicted by conventional electron counting theories, and both also possess unusually long metal-metal bonds that may be related to these anomalous electron configurations. Crystal data for2, space group Pna21,a=19.951(3) Å,b=9.905(2) Å,c=17.180(2) Å,Z=2, 1844 reflections,R=0.036; for3, space group Pna21,α=13.339(1) Å,b=14.671(2) Å,c=11.748(2) Å, α=100.18(1)°, β=95.79(1)°, γ=83.671(9)°,Z=2, 3127 reflections,R=0.026. 相似文献
11.
《Journal of organometallic chemistry》1990,393(2):C30-C33
The reactions of [Ru3(μ-H)(μ-ampy)(CO)9] (1) (Hampy = 2-amino-6-methylpyridine) with one or two equivalents of PPh2H lead to the complexes [Ru3(μ-H)(μ3-ampy)(CO)8(PPh2H)] (2) or [Ru3(μ-H)(μ3-ampy)(CO)7(PPh2H)2] (3), in which the PPh2H ligands are cis to the bridging NH fragment and cis to the hydride. Complex 2 can be transformed in refluxing THF into the phosphido-bridged derivative [Ru3(μ3-ampy)(μ-PPh2)(μ-CO)2(CO)6] (4), which contains the PPh2 ligand spanning one of the two RuRu edges unbridged by the amido moiety, and presents an extremely high 31P chemical shift of 386.9 ppm. Under similar conditions, complex 3 gives a mixture of two isomers of [Ru3(μ-H)(μ3-ampy)(μ-PPh2)2(CO)6] in a 5:1 ratio; the major product (5) has a plane of symmetry, whereas the minor one (6) is asymmetric. 相似文献
12.
Shariff E. Kabir Tasneem A. Siddiquee Edward Rosenberg Ryan Smith Michael B. Hursthouse K. M. Abdul Malik Kenneth I. Hardcastle Mandana Visi 《Journal of Cluster Science》1998,9(2):185-199
The reactions of [Ru3(CO)10(μ-dppm)] 4 with quinolines afforded [Ru3 (μ-CO)(CO)7{μ3-η2-P(C6H5)CH2P(C6H5)2)}{μ-η2-C9H5(R)N}] (8, R = 4-Me; 9, R = H) as the major products along with small amounts of known compound [Ru3(CO)9{μ3-η3-P(C6H5)CH2P(C6H5)(C6H4)}] 5. The molecular structure of 8 has been determined by single crystal X-ray studies. The reaction of 5 with 4-methylquinoline in refluxing cyclohexane afforded 8 and two known dinuclear compounds, [Ru2(CO)6{μ-CH2P(C6H5)(C6H4)P(C6H5}] 10 and [Ru2(CO)6 {μ-(C6H4)P(C6H5)(CH2)P(C6H5}] 11, in 40, 12, and 10% yields, respectively. The compounds 10 and 11 are also formed from the thermolysis of 4 in addition to the major compound 5. The solid state structure of the previously reported [Ru3(CO)10(η-H){μ-η2-C9H6N}] 2a is also reported for comparison. 相似文献
13.
Kayla J. Pyper David K. Kempe Jade Y. Jung Li-Hsing J. Loh Nigel Gwini Benjamin D. Lang Brittney S. Newton Jonathan M. Sims Vladimir N. Nesterov Gregory L. Powell 《Journal of Cluster Science》2013,24(3):619-634
Microwave heating allows for the high-yield, one-step synthesis of the known triosmium complexes Os3(μ-Br)2(CO)10 (1), Os3(μ-I)2(CO)10 (2), and Os3(μ-H)(μ-OR)(CO)10 with R = methyl (3), ethyl (4), isopropyl (5), n-butyl (6), and phenyl (7). In addition, the new clusters Os3(μ-H)(μ-OR)(CO)10 with R = n-propyl (8), sec-butyl (9), isobutyl (10), and tert-butyl (11) are synthesized in a microwave reactor. The preparation of these complexes is easily accomplished without the need to first prepare an activated derivative of Os3(CO)12, and without the need to exclude air from the reaction vessel. The syntheses of complexes 1 and 2 are carried out in less than 15 min by heating stoichiometric mixtures of Os3(CO)12 and the appropriate halogen in cyclohexane. Clusters 3–6 and 8–10 are prepared by the microwave irradiation of Os3(CO)12 in neat alcohols, while clusters 7 and 11 are prepared from mixtures of Os3(CO)12, alcohol and 1,2-dichlorobenzene. Structural characterization of clusters 2, 4, and 5 was carried out by X-ray crystallographic analysis. High resolution X-ray crystal structures of two other oxidative addition products, Os3(CO)12I2 (12) and Os3(μ-H)(μ-O2CC6H5)(CO)10 (13), are also presented. 相似文献
14.
Françoise Van Gastel Lisa Agocs Andrew A. Cherkas John F. Corrigan Simon Doherty Ravindranath Ramachandran Nicholas J. Taylor Arthur J. Carty 《Journal of Cluster Science》1991,2(2):131-136
Thecloso octahedral cluster Ru4(CO)11(μ4-PPh)(μ4-S)1 and selenium and tellurium analogues, the first examples of unsaturated ruthenium clusters with a planar metal core and different main group 15 and 16 atoms have been synthesized fromnido Ru4(CO)13(μ3-PPh). An X-ray analysis of1 and Ru4(CO)10(μ4-PPh)(μ4-Se)(PEt3)2a has confirmed thetrans disposition of phosphorus and group 16 main group fragments. 相似文献
15.
Paul R. Raithby Jack Lewis Catherine A. Morewood M. Carmen Ramirez de Arellano Gregory P. Shields 《Journal of Cluster Science》2006,17(1):13-26
Thermolysis of [Ru3(CO)12] in cyclohexene for 24 h affords the complexes [Ru(CO)3(η4-C6H8)] (1), [Ru3H2(CO)9(μ2-η1:η2:η1-C6H8)] (2), [Ru4(CO)12(μ4-C6H8)] (3) [Ru4(CO)9(μ4-C6H8)(η6-C6H6)] (4a and 4b, two isomers) and [Ru5(CO)12(μ4-η2-C6H8)(η4-C6H8)] (5), where 1, 3, 4a and 4b have been previously characterised as products of the thermolysis of [Ru3(CO)12] with cyclohexa-1,3-diene. The molecular structures of the new clusters 2 and 5 were determined by single-crystal X-ray crystallography, showing that two conformational polymorphs of 5 exist in the solid state, differing in the orientation of the cyclohexa-1,3-diene ligand on a ruthenium vertex. 相似文献
16.
The trinuclear osmium carbonyl cluster, [Os3(CO)10(MeCN)2], is allowed to react with 1 equiv. of [IrCp1Cl2]2 (Cp1 = pentamethylcyclopentadiene) in refluxing dichloromethane to give two new osmium–iridium mixed-metal clusters, [Os3Ir2(Cp1)2(μ-OH)(μ-CO)2(CO)8Cl] (1) and [Os3IrCp1(μ-OH)(CO)10Cl] (2), in moderate yields. In the presence of a pyridyl ligand, [C5H3N(NH2)Br], however, the products isolated are different. Two osmium–iridium clusters with different coordination modes of the pyridyl ligand are afforded, [Os3IrCp1(μ-H)(μ-Cl)(η3,μ3-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp1(μ-Cl)2 (η2,μ3-C5H3N(NH)Br)(CO)7] (4). All of the new compounds are characterized by conventional spectroscopic methods, and their structures are determined by single-crystal X-ray diffraction analysis. 相似文献
17.
《Journal of organometallic chemistry》1991,409(3):C15-C18
The interaction of [(η5-C5Me4R)Ru(CO)2]2 (1a: R = Me, 1b: R = Et) with yellor arsenic, As4, affords besides the pentaarsaruthenocenes [(η5-As5)Ru(η5-C5Me4R)] (2a, 2b) the tetranuclear clusters [{(η5-C5Me4R)Ru}3Ru(η3-As3)(μ3,η3-As3)(μ3-As)3] (3a, 3b). The structure of 2b and 3b has been elucidated by X-ray analysis. 相似文献
18.
《Journal of organometallic chemistry》1995,503(2):C43-C45
Two hexaruthenium carbonyl clusters [Ru6(CO)15(μ-CO)2(μ4-NH) (μ-OMe){μ3-η2-N(H)C(O)OMe}] and [Ru6(CO)16(μ-CO)2-(μ4-NH)(μ-OMe)(μ-NCO)]2 have been isolated from the pyrolysis of H2Ru3(CO))9NOCH3, and single-crystal X-ray structure analysis shows that both 1 and 2 have a square planar arrangement of four ruthenium atoms capped by a μ4-nitrene ligand, with two additional ruthenium atoms bridging two opposite RuRu edges of the square base to form a ‘boat’ form metal framework. 相似文献
19.
20.
The first order rate constants for the tautomerization of the hydrio(alkynyl) clusters Ru3Pt(μ-H){μ4-ν2-C ≡ C1Bu}(CO)9(L2);1a: L2 = dppe,1b; L2 = dppet,1c; L2 = dppp and1d; L2 =S,S-dppb to the corresponding vinylidene clusters Ru3Pt{μ4-ν2-C = C(H)tBu}(CO)9(L2)2 have been measured, and they follow the orser1d <1a <1b ~1c. The reactions involving1a and1d exhibit an inverse kinetic deuterium isotope effect. The structures of1b, 2b, 2c, and2d were determined by X-ray crystallography, and are compared with those of1a and2a which have been previously reported. Crystal data for1b, space groupPbca,a = 13.338(4) Å,b = 17.771(6) Å,c = 36.092(8) Å,Z = 8,R(R w) = 0.059(0.058) for 2342 absorption corrected, observed data; for2b, space group P21/n,a = 10.566(2) Å,b = 20.234(5) Å,c = 20.270(3) Å,β = 96.11(1)°,Z = 4,R(R w) = 0.043(0.053) for 5865 absorption corrected, observed data; for2c, space group P21/n,a = 14.211(5) Å,b = 19.534(2) Å,c = 15.870(2) Å,β = 100.81(2)°,Z = 4,R(R w) = 0.055(0.031) for 6566 absorption corrected, observed data: for2d, space group P212121,a = 12.309(4) Å,b = 19.047(6) Å,c = 19.206(4) Å,Z = 4,R(R w) = 0.055(0.053) fpr 2151 absorption corrected, observed data. The fluxional behavior of1d and1e (which consists of two interconverting isomers) has been examined by variable temperature13C NMR spectroscopy and by31P EXSY. 相似文献