Large Trans Influence Research Articles

Synthesis, structure and NMR spectroscopy of some rhodium(III) cyclometallated Schiff's base complexes derived from 2-benzylidene-3-methylpyridines. Crystal structure of [RhHI{2-(3-nitrobenzylidene)-3-methylpyridine}; (PPh 3) 2

The Schiff's base derived from 2-amino, 3-methylpyridine and an aryl aldehyde reacts with either RhCI(PPh 3) 3 or [Rh(μ-C1)(cyclooctene) 2] 2 in the presence of four equivalents of L (L = PPh 3, P(4-C1C 6H 4) 3, P(cyclohexyl) 3, AsPh 3, SbPh 3) to give a Rh III cyclometallated complex ( 2), in which the imine CH bond has oxidatively added to the metal. The complexes 2 react with reagents such as Br -, CN -, CH 3I, CNR (R = cyclohexyl, t-butyl), P(OCH 3) 3, CO, to give substitution products ( 3), in which the Cl has been replaced. The complexes 2 and 3, as well as some few Ir III analogs ( 4), have been isolated and characterized using 1 H, 31 P, and (occasionally) 13C NMR spectroscopy. The crystal structure of the complex RhHI{2-(3-nitrobenzylidene)-3-methylpyridine} (PPh 3) 2 ( 3b) has been determined by X-ray diffraction. The complex shows a distorted octahedral structure with the following bond distances (Å) and angles (°): Rh-I, 2.771(2); Rh-N(1), 2.15(1); Rh-C(7′), 1.98(2); Rh-P(1), 2.326(5); Rh-P(2) 2.332(5); P-Rh-P, 159.7(2), N(1)-Rh-C(7′), 78.5(6). In the light of the NMR and X-ray data, it is suggested that the C(R)N moiety exerts a large trans influence.

Novel pathways for ligand substitution reactions of dinuclear platinum(I) complexes

The terminal halide and/or triphenylphosphine ligands L in dinuclear platinum(I) complexes (Pt/sub 2/L/sub 2/(..mu..dppm)/sub 2/)/sup n /sup +// (where dppm = Ph/sub 2/PCH/sub 2/PPh/sub 2/) undergo ready substitutions. The reaction of (Pt/sub 2/Cl/sub 2/(..mu..-dppm)/sub 2/), abbreviated (Cl--Cl), with PPh/sub 3/ follows a second-order rate law, with kappa = 15.2 +/- 0.7 M/sup -1/ s/sup -1/ at 25/sup 0/C in CH/sub 2/Cl/sub 2/. The product is exclusively (Cl--PPh/sub 3/)/sup +/; (Ph/sub 3/P--PPh/sub 3/)/sup 2 +/ forms only in a more polar solvent like methanol. The complex (Ph/sub 3/P--PPh/sub 3/)/sup 2 +/ reacts in CH/sub 2/Cl/sub 2/ with halide ions (X/sup -/ = Cl/sup -/, Br/sup -/, and I/sup -/) also to yield (X--PPh/sub 3/)/sup +/. In the presence of inert salts such as perchlorates, the reaction proceeds by rate-limiting dissociation of PPh/sub 3/, unusual for square-planar, 16-electron platinum, but further evidence for the large trans influence of the metal-metal bond. In the absence of such salts, however, the reaction occurs in three distinct kinetic stages, although eventually leading to (Cl--PPh/sub 3/)/sup +/. One of the intermediates can be stabilized at low temperature; its /sup 31/P NMR spectrum identifies it (for X/sup -/ = I/sup -/ and Cl/sup -/) as a speciesmore » containing both bridging and chelating dppm (Pt/sub 2/(X)(PPh/sub 3/)(..mu..-dppm)(eta-dppm))/sup +/. Substitution of PPh/sub 3/ in (Ph/sub 3/--PPh/sub 3/)/sup 2 +/, like the A-frame forming reactions of the same complex, starts with the dissociation of one arm of a bridging dppm ligand.« less

195Pt, 119Sn and 31P NMR studies of alkyl, aryl and acyl trichlorostannate complexes of platinum(II). The crystal structure of trans-[Pt(SnCl 3)(COC 6H 5)(PEt 3) 2

195Pt, 119Sn and 31P NMR characteristics of the complexes trans-[Pt(SnCl 3)(carbon ligand)(PEt 3) 2] ( 1a- 1e) are reported, (carbon ligand = CH 3 ( 1a), CH 2Ph ( 1b), COPh ( 1c), C 6Cl 5 ( 1d), C 6Cl 4Y ( e); Y = meta- and para-NO 2, CF 3, Br, H, CH 3, OCH 3, or Pt(SnCl 3)(PEt 3) 2. The values of 1 J( 195Pt, 119Sn) vary from 2376 to 11895 Hz with the COPh ligand having the smallest and the C 6Cl 5 ligand the largest value, making a total range for this coupling constant, when the dimer syn- trans-[PtCl(SnCl 3)(PEt 3)] 2 is included, of ca. 33000 Hz. In the meta- and para-substituted phenyl complexes 1 J( 195Pt, 119Sn) (a) is greater for electron-withdrawing substituents, (b) varies more for the meta-substituted derivatives (5634 to 7906 Hz) than for the para analogues (6088 to 7644 Hz) and (c) has the lowest values when the Pt(SnCl 3)(PEt 3) 2 group is the meta- or para-substituent. The direction of the change in 1 J( 195Pt, 119Sn) is opposite to that found for 1 J( 195Pt, 119P). For the aryl complexes linear correlations are observed between δ( 119Sn), 1 J( 195Pt, 119Sn), 1 J( 195Pt, 31P), 1 J( 119Sn, 31P) and the Hammett substituent constant σ n . δ( 119Sn) and 1 J( 195Pt, 119Sn) are related linearly to v(Pt-H) in the complexes trans-[PtH(C 6H 4Y)(PEt 3) 2]; δ( 119Sn) and δ( 1H) (hydride) are also linearly related. Based on 1 J( 195Pt, 119Sn), the acyl ligand is suggested to have a very large NMR trans influence. The differences in the NMR parameters for ( 1a-e) are rationalized in terms of differing σ- and π-bonding abilities of the carbon ligands. The structure of 1c has been determined by crystallographic methods. The complex has a slightly distorted square planar geometry with trans-PEt 3 ligands. Relevant bond lengths (Å) and bond angles (°) are: PtSn, 2.634(1), PtP, 2.324(4) and 2.329(4), PtC, 2.05(1); PPtP, 170.7(6), SnPtC, 173.0(3), SnPtP, 92.1(1), 91.7(1), PPtC, 88.8(4) and 88.3(4). The PtSn bond separation is the longest yet observed for square-planar platinum trichlorostannate complexes, and would be consistent with a large crystallographic trans influence of the benzoyl ligand. The PtSn bond separation is shown to correlate with 1 J( 195Pt, 119Sn).

The structure of 1-phenyl-3-trifluoromethyl-1, 3-propanedionatobis(triphenylphosphite)rhodium(I)

The crystal structure of 1-phenyl-3-trifluoromethyl-1,3-propanedionatobis(triphenylphosphite)rhodium(I), [Rh(TFBA)(P(OPh) 3) 2] has been determined by means of single crystal X-ray diffraction. The structure was refined to a R value of 0.043.2719 Independant observed reflections were used. The unit cell is orthorombic, with space group Pca2 1, a = 20.761 Å, b = 10.790 Å, c = 19.035 Å and Z = 4. The compound was prepared by substitution of the two carbonyl groups in the Rh(I) complex, 1-phenyl-3-trifluoromethyl-1,3-propanedionatobiscarbonylrhodium(I), [Rh(TFBA)CO) 2], by triphenylphosphite in methanolic medium. The significant difference between the two Rh-P bond lengths reveals that the oxygen atom nearest to the phenyl group has a larger trans influence than the other oxygen atom.

The crystal structure of 8-hydroxyquinolinato(1,5-cyclooctadiene)rhodium(I)

8-Hydroxyquinolinato(1,5-cyclooctadiene)rhodium(I), [Rh(oxine)(COD)], was synthesized by the reaction between [RhCl(COD)] 2, and the sodium salt of 8-hydroxyquinoline. This compound crystallizes in the triclinic space group P − 1 with a = 7.701 Å, b = 10.062 Å, c = 9.802 Å, α 72.82°, β = 108.03° and γ = 99.42° and with 2 molecules per unit cell. The crystal structure was determined from 2917 observed reflections obtained with a computer-automated diffractometer. The final R-value was 0.062. The RhS (1) and RhS(2) bond distances (S(1) and S(2) are the centres of the double bonds of 1,5-cyclooctadiene), as well as the carboncarbon double bond lengths of 1,5-cyclooctadiene, indicate that the nitrogen atom of the chelate ring has a larger trans influence than the oxygen atom.

The crystal structure of 1,1,1,-trifluoro-5,5-dimethylpentanedionato-carbonyltriphenylphosphinerhodium(I)

1,1,1-Trifluoro-5,5-dimethylpentanedionatocarbonyltriphenylphosphinerhodium(I), [Rh(TFDMAA)(CO)(PPh 3)], was synthesized by means of the reaction between [Rh(TFDMAA)(CO) 2] and PPh 3. It crystallizes in the triclinic space group P 1 with a = 9.215 Å, b = 10.584 Å, c = 13.760 Å, α = 107.61°, β = 104.79°, λ = 83.54° and with two molecules per unit cell. The crystal structure was determined from 2980 observed reflections that were obtained with an automated diffractometer. The final R value was 0.046. The result of this structure determination indicates that the oxygen atom nearest to the CF 3-group has a larger trans influence than the other oxygen atom of the β-diketone since it was the carbonyl group trans to the first mentioned oxygen atom that was substituted during the reaction with PPh 3. This result contradicts other similar structure determinations.

The crystal structure of N-benzoyl-N-phenylhydroxylaminocarbonyltriphenylphosphinerhodium(I)

N-Benzoyl-N-phenylhydroxylaminocarbonyltriphenylphosphinerhodium(I), [Rh(BPHA)(CO)(PPh 3)], was prepared by the reaction between [Rh(BPHA)(CO) 2] and triphenylphosphine and recrystallized from acetone. The crystal structure of the compound was determined from 4572 unique observed reflections obtained with a computer automated diffractometer. The unit cell is triclinic with a = 14.723 Å, b = 9.567 Å, c = 10.328 Å, α = 107.8°, β = 97.2°, γ = 82.9°, Z = 2 and space group P 1 . The final R-value was 0.042. The structure determination showed that the carbonyl group trans to the oxygen atom bonded to the nitrogen atom of the chelate ring was not substituted during the reaction. This result indicates that this oxygen atom of BPHA has a smaller trans influence than the other oxygen atom. The RhO bond distances indicate that the triphenylphosphine ligand has a larger trans influence than the carbonyl group.

The crystal structure of diiodo(( o-methylthiophenyl)diphenylphosphine)palladium(II), a complex exhibiting a large structural trans influence

The crystal structure of the title compound has been determined by conventional X-ray diffraction techniques. The red diamond-shaped crystals are monoclinic, space group P2 1/ n, a 8.914(4), b 16.090(12), c 14.991(5) Å, β 95.97(2)°, V 2138.44 Å 3, Z = 4. Refinement by full-matrix least-squares methods employed anisotropic thermal parameters for all non-hydrogen atoms and isotropic temperature factors for hydrogen atoms, and returned final residuals of R = 0.028 and R w = 0.028. The complex is monomeric, with a square planar coordination geometry comprising the S and P atoms of the bidentate ( o-methylthiophenyl)diphenylphosphine ligand and the two iodine atoms. The PdI distance trans to P is 2.658(1) Å whereas that trans to S is 2.602(1) Å. The difference of 56 standard deviations illustrates the greater structural trans influence of phosphine over thioether donors. The PdP and PdS distances of 2.250(2) and 2.288(2) Å, respectively, are normal. Two phenyl hydrogen atoms approach the Pd atom in the axial regions above and below the square plane at distances of 2.98 and 2.99 Å.

The crystal structure of 8-hydroxyquinolinatocarbonyltriphenylphosphinerhodium(I)

The crystal structure of 8-hydroxyquinolinatocarbonyltriphenylphosphine, C 28H 21O 2NPRh, was determined from 2995 unique observed reflections obtained with a computer automated diffractometer. The unit cell is triclinic with a = 14.154 Å, b = 9.984 Å, c = 9.409 Å, α = 116.16°, β = 90.09°, γ = 99.60°, Z = 2 with space group P 1 . Refinement of the data with anisotropic thermal parameters converged to R = 4.9%. The compound was prepared by the reaction between [Rh(oxine)(Co) 2] and triphenylphosphine. The structure determination shows that the carbonyl group trans to the nitrogen atom of the 8-hydroxyquinolinato ligand was substituted by the triphenylphosphine ligand, which indicate that the nitrogen atom of the chelate ring has a larger trans influence than the oxygen atom.

The crystal structure of tropolonatocarbonyltriphenylphosphinerhodium(I)

Tropolonatocarbonyltriphenylphosphinerhodium(I) crystallizes in the triclinic space group P 1 with a = 8.843, b = 10.555, c = 13.575 Å, α = 88.95, β = 103.12 and γ = 96.06°. The compound was prepared by the reaction between [Rh(TROP)(CO) 2] and triphenylphosphine. 3030 Observed reflections were used for the structure determination. The final R value was 0.058. The rhodiumoxygen bond lengths were 2.034 and 2.081 Å. The results indicate that the triphenylphosphine ligand has a larger trans-influence than the carbonyl group.

The trans-influence in polyenyl—metal complexes; The crystal and molecular structure of hydrido-(η-pentamethylcyclopentadienyl)bis(triphenylphosphine)-rhodium(III) hexafluorophosphate

The structure of [Rh(η-C 5Me 5)H(PPh 3) 2]PF 6 has been determined by 1H NMR studies and a single-crystal X-ray analysis. The compound crystallises in the orthrhombic space group P2 12 12 1 with lattice constants a 12. 926(3), b 15.216-(3) and c = 20.957(4) Å, with Z = 4. The structure was determined using diffractometer data and by least-squares techniques to R = 0.0887 based on 2805 independent reflections with F 0⪢4 o( F 0). The geometry about the metal atom may be inferred to be a “piano-stool” arrangement with the C 5Me 5 ring representing the seat and the PPh 3 and H ligands the legs, although the hydrogen atom was not directly located in the crystallographic analysis. The observed distortions in the C 5Me 5 ring may be attributed to the large trans-influence of the hydrido ligand.

ChemInform Abstract: CRYSTAL AND MOLECULAR STRUCTURE OF (TRIFLUOROMETHANESULFONATO)(3‐(DIETHYLAMINO)PROPIONYL)(DIETHYLAMINE)PALLADIUM(II): AN EXAMPLE OF A VERY LARGE TRANS INFLUENCE

Chemischer InformationsdienstVolume 10, Issue 29 Physical Organic Chemistry ChemInform Abstract: CRYSTAL AND MOLECULAR STRUCTURE OF (TRIFLUOROMETHANESULFONATO)(3-(DIETHYLAMINO)PROPIONYL)(DIETHYLAMINE)PALLADIUM(II): AN EXAMPLE OF A VERY LARGE TRANS INFLUENCE O. P. ANDERSON, O. P. ANDERSONSearch for more papers by this authorA. B. PACKARD, A. B. PACKARDSearch for more papers by this author O. P. ANDERSON, O. P. ANDERSONSearch for more papers by this authorA. B. PACKARD, A. B. PACKARDSearch for more papers by this author First published: July 17, 1979 https://doi.org/10.1002/chin.197929076AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume10, Issue29July 17, 1979 RelatedInformation

Crystal and molecular structure of (trifluoromethanesulfonato)(3-(diethylamino)propionyl)(diethylamine)palladium(II): an example of a very large trans influence

Crystal and molecular structure of (trifluoromethanesulfonato)(3-(diethylamino)propionyl)(diethylamine)palladium(II): an example of a very large trans influence

The Trans-Influence In Platinum(II) Complexes. An Application of 129I-Mössbauer Spectroscopy

The 129I-Mössbauer spectra of several cis-diioda-and two hydridoiodo-platinum(II) complexes have been obtained at 4.2°K. The quadrupole coupling constants of the cis complexes vary systematically with the nature of the neutral ligands, indicating the operation of a Trans-influence. The values for the hydrides are very low, showing a large trans-influence for this ligand.

The trans-influence of acyl groups in trans-[PtCl(COR)(PPh 3) 2] complexes

The v(PtCl) band appears at 254–272 cm −1 in a range of acyl—platinum complexes, trans-[PtCl(COR)(PPh 3) 2], indicating that the acyl groups have a large trans-influence.

Crystal and molecular structure of chloro-(2-methoxycyclo-octa-1,5-dienyl)pyridineplatinum

Crystals of the title compound are monoclinic, a= 9·84 ± 0·01, b= 18·50 ± 0·02, c= 8·15 ± 0·01 A, β= 104°± 10′, Z= 4, space-group P21/c. The structure was determined from photographic data by conventional Patterson and Fourier methods and refined by least-squares techniques to R 0·086 for 1445 independent reflections. The structure consists of monomeric units in which the central atom is in an essentially square planar configuration. The cyclo-octadienyl ligand is bonded to the platinum atom by both a π-olefinic bond and a σ-bond, the pyridine being trans to the latter. The long Pt–N distance [2·02(2)A] results from the large trans-influence of the σ-bonded carbon atom.