Katarzyna Wajda-Hermanowicz

RHODIUM(I) ACETYLACETONATO COMPLEXES WITH FUNCTIONALIZED PHOSPHINES

Abstract Rhodium(I) complexes [Rh(acac)(CO)(PR3)] with 1,3,5-triaza-7-phosphatricyclo[3.3.1.13,7]decane (tpa), tris(2-cyanoethyl)phosphine (cyep), tris(3-sodium sulfonatophenyl)phosphine (tppts), tris(o-methoxyphenyl)phosphine (ompp), tris(p-methoxyphenyl)phosphine (pmpp), tris(2,4,6-trimethoxyphenyl)phosphine (tmpp), PPh2(pyl), PPh(pyl)2 and P(pyl)3 (pyl=2-pyridyl) have been synthesized and characterized with 1H- and 31P-NMR and IR spectra. The measured 31P coordination chemical shifts, Δδ31P{1H}, correlate well with ν(CO). Differences in 1H chemical shifts of methyl groups of acac ligand, ΔδMe, depend both on steric and electronic properties of phosphine ligand. Thus ΔδMe increases with decrease of Δδ31P{1H} and increases with increase of the cone angle of phosphine. Catalytic activity of complexes with tpa, cyep and tppts has been investigated. They are efficient catalysts for hydrogenation of C C and C O bonds, isomerization of alkenes and hydroformylation of alkenes. The mechanism of isomerization of allyl alcohol to propanal has been elucidated.

Rhodium carbonyl complexes of thetrans-[RhCl(CO)(PR3)2] type with pyridylphosphines

SummaryTrans-[RhCl(CO)(PR3)2] complexes [PR3=tris-(2-pyridyl)phosphine {P(2-pyl)3}, phenylbis(2-pyridyl)phosphine {PPh(2-pyl)2} or tris(3-pyridyl)phosphine {P(3-pyl)3}] have been synthesized and examined by spectroscopic methods (i.r., u.v.-vis,31P{1H} n.m.r.,1H n.m.r.). In solution the P(2-pyl)3 and PPh(2-pyl)2 complexes exhibit equilibrium between the pentacoordinate state, with one of the phosphine molecules coordinated via nitrogen and phosphorus, and complexes with the phosphine coordinated only through nitrogens.

Properties and reactivity of the new [Ir4(μ-CO)3(CO)5(μ-PR3)(PR3)2] clusters, (PR3 = PPHxpyl3−x, pyl = 2-pyri)

Abstract The complex Ir 4 (CO) 12 was shown to react with pyridylphosphines to give [Ir 4 (μ-CO) 3 (CO) 5 (μ-PPh 2 pyl) 2 ] ( 1 ) [Ir 4 (μ-CO) 3 (CO) 5 (μ-PPhpyl 2 )(PPhpyl 2 ) 2 ] ( 2 ) and [Ir 4 (μ-CO) 3 (CO) 5 )(μ-Ppyl 3 )(Ppyl 3 ) 2 ] ( 3 ) in which one of the phosphine ligands bridges through coordination of P and N atoms. Clusters 1 – 3 were characterized by 1 H, 31 P NMR and IR spectroscopy. Variable-temperature 1 H, 31 P and 13 C NMR spectra of 1 – 3 were investigated and the results are discussed. In solution under CO complexes 1 – 3 are in equilibrium with the clusters [Ir(μ-CO) 3 (CO) 6 (PR 3 ) 3 ].

Synthesis, reactivity and structure of [Ir4(μ-CO)3(CO)5(μ-PPh2pyl)(PPh2pyl)2]

Abstract Ir( 4 (CO) 12 reacts with P(Ph 2 pyl) 3 giving [Ir 4 (μ-CO) 3 (CO) 5 (μ-PPh 2 pyl)(PPh 2 pyl) 2 ] containing one phosphine bridging ligand coordinating via P and N atoms and [Ir 4 (μ-CO) 3 (CO) 6 (PPh 2 pyl) 3 ] which in solution is at equilibrium with the former cluster.

Carbonylrhodium complexes with pyridylphosphines: [Rh(chel)(CO)(PPhxpyl3−x)]

SummaryDiphenyl(2-pyridyl)phosphine (PPh2pyl), phenylbis(2-pyridyl)-phosphine (PPhpyl2) and tris(2-pyridyl)-phosphine (Ppyl3) react with [Rh(acac)(CO)2] (acac=acetylacetonate) and Rh(8-oxy)(CO)2(8-oxy=8-hydroxyquinolinate) yielding [Rh(chel)(CO)(PPhxpyl3−x)]. The properties of these complexes were examined by spectral (i.r.,u.v.-vis,31P n.m.r.) and chemical methods.

A new convenient method for the high-yield synthesis of Ir4(CO)12

Abstract The complex Ir4(CO)12 has been prepared by a new, simple method, involving heating of solutions of IrIII or IrIV chlorides in 98% formic acid. Reaction at 100°C gave pure Ir4(CO)12 in 100% yield.

Crystal structure of tri-μ-carbonyl-pentacarbonyl{diphenyl-2-pyridylphosphine-(P,N)}bis{diphenyl-2-pyridylphosphine-(P)}tetrairidium(0), [Ir4(CO)8(PPh2pyl)3]

The structure of the title tetranuclear cluster, C59H42N3O8P3Ir4, was determined by X-ray analysis. It crystallizes in the monoclinic space groupC2/c. The unit cell parameters are:a =47.277(6),b=10.519(3),c=23.025(4) Å, β=105.77(1)°. The iridium atoms form a nearly regular tetrahedron. Between Ir4 and N336 atoms exists a relatively strong bond, thus one of the phosphine ligands is bridging one coordinatingvia P and N atoms.

Far infrared and Raman spectra, normal coordinate analysis and potential energy distribution for the dimeric rhodium(II) complexes with oxygen and nitrogen donor ligands

Abstract Infrared and Raman spectra in the 30–500 cm −1 region have been recorded for solid rhodium(II) complexes with formate, acetate, phenanthroline, dipyridyl and mandelate ligands. The normal coordinate analysis and potential energy distribution were performed for the Rh 2 O 4 N 4 Cl 2 , dimeric molecular system of C 2 v symmetry.

A Study on the Condensation Reaction of 4-Amino-3,5-dimethyl-1,2,4-triazole with Benzaldehydes: Structure and Spectroscopic Properties of Some New Stable Hemiaminals

Studies on the stable hemiaminals and Schiff bases formation in the reaction of substituted benzaldehydes with primary 3,5-dimethyl-1,2,4-triazole 4-amine were carried out under neutral conditions. These products were investigated by IR, Raman, MS, 1H- and 13C-NMR spectra as well as by X-ray crystallography. The effect of reaction conditions: temperature, polarity of the solvents utilized, substrate concentration and the ortho and para benzaldehyde substituents on the yield of products was also examined.

Binuclear rhodium(II) complexes with leucine and proline

The dimeric rhodium(II) complexes [Rh2(leu)4(H2O)2]- (ClO4)4 and [Rh2(pro)4(H2O)2](ClO4)4 have been prepared and characterized by elemental analyses, i.r., u.v.–vis. and 1H-n.m.r. spectroscopy. The amino acid molecules are coordinated as bridging ligands via their carboxylato groups. Cyclic voltammetry in DMF has shown that the complexes undergo a quasi-reversible reduction to yield dimers containing a Rh23+ core. Oxidation processes within the 0–1.5V range were not observed.