Giuseppe Cardaci - Academia.edu (original) (raw)
Papers by Giuseppe Cardaci
Zeitschrift für Naturforschung B, 1972
The polarographic behaviour of [(C2H5)4N] ⊕ [Fe(CO)3NO⊖] has been investigated at the mercury dro... more The polarographic behaviour of [(C2H5)4N] ⊕ [Fe(CO)3NO⊖] has been investigated at the mercury dropping electrode and platinum stationary electrode. It was found that the complex displays two anodic and one cathodic waves. On the basis of the results obtained a mechanism is proposed and discussed.
Polyhedron, 1983
The dihaptoiminoacyI complex [Fe(C0)2 (PMe3)2(q2-CMe=N-CMe3)]+ I-was obtained by reaction of [Fe(... more The dihaptoiminoacyI complex [Fe(C0)2 (PMe3)2(q2-CMe=N-CMe3)]+ I-was obtained by reaction of [Fe(CO)z(PMes)zMeI] and tertbutylisocyanide. The structure of the complex was determined by an X-ray structure analysis.
Organometallics, 1998
The reactions of complexes trans, cis-M(PMe 3) 2 (CO) 2 (Me)I (M) Fe (1a), Ru (1b)) with N,O liga... more The reactions of complexes trans, cis-M(PMe 3) 2 (CO) 2 (Me)I (M) Fe (1a), Ru (1b)) with N,O ligands [2-acetylpyridine (2-apy), 2-benzoylpyridine (2-bzpy), and 2,2′-dipyridyl ketone (2,2′-dpk)] in the presence of NaBPh 4 afford a mixture of the two possible stereoisomers trans-[M(PMe 3) 2 (CO)(COMe)(N, O)]BPh 4 having the N arm cis (A) or trans (B) to the acetyl group. The stereochemistry of the complexes was determined by 1 H NOESY NMR spectra. For all the iron complexes the major stereoisomer is B, while for ruthenium complexes it is A. When A/B mixtures are left in methylene chloride, the concentration of A increases, indicating that A and B are the thermodynamic and kinetic reaction products, respectively. Furthermore, the more basic the N,O ligands, the more B stereoisomer that forms. The solid-state structure of 4b was obtained using single-crystal X-ray diffraction. For all the complexes , the ion-pair structures and the localization of the counterion in solution with respect to the organometallic moiety were investigated by the detection of interionic contacts in the 1 H NOESY NMR spectra. Specific interactions were observed that indicate that the counterion is localized in solution in front of the face determined by PMe 3 and the two arms of the N,O ligands.
Organometallics, 2000
The molecular self-diffusion coefficients of the complexes trans-[Ru(PMe 3) 2 (CO)(COMe)(pz 2-CH ... more The molecular self-diffusion coefficients of the complexes trans-[Ru(PMe 3) 2 (CO)(COMe)(pz 2-CH 2)]BPh 4 and trans-[Ru(PMe 3) 2 (CO)(COMe)(pz 2-BH 2)] have been measured by pulsed field gradient spin-echo NMR measurements in nitromethane, chloroform, and methylene chloride as a function of concentration. By using the neutral complex as reference with the assumption that it does not undergo associative processes, clear indications of the presence of ions (in nitromethane), ion pairs (in chloroform at low concentration), and ion quadruples (in chloroform at high concentration) have been obtained.
Journal of Organometallic Chemistry, 1975
Abstract The reaction between π-(PhCHCHCOR)Fe(CO) 3 (R = H, CH 3 , Ph) and L (L = PPh 3 , AsPh 3... more Abstract The reaction between π-(PhCHCHCOR)Fe(CO) 3 (R = H, CH 3 , Ph) and L (L = PPh 3 , AsPh 3 , SbPh 3 ) in acetone occurs in two steps. The products of the first step are the π-(PhCHCHCOR)Fe(CO) 3 L complexes, which in the second step yield Fe(CO) 3 L 2 and π-(PhCHCHCOR)Fe(CO) 2 L. The kinetic results indicate that the first step is association of the substrate with the ligand. The variation of the ratio [Fe(CO) 3 L 2 ]/[π-(PhCHCHCOR)Fe(CO) 2 L] with L suggests three different reaction paths for the second step.
Journal of Organometallic Chemistry, 1972
Journal of Organometallic Chemistry, 1974
Abstract The reaction: (π-CH 2 =CHPh)Fe(CO) 4 + (2α)PPh 3 → α Fe(CO) 4 PPh 3 + (1α)Fe(CO) 3 (PP... more Abstract The reaction: (π-CH 2 =CHPh)Fe(CO) 4 + (2α)PPh 3 → α Fe(CO) 4 PPh 3 + (1α)Fe(CO) 3 (PPh 3 ) 2 + CH 2 =CHPh + (1α)CO has been studied in dichloromethane, acetone, acetonitrile, isopropyl ether and n-hexane. The kinetics indicate that the reaction mechanism is the same as that in toluene. The solvent and temperature effects on the α/1α ratio further confirm the nature of the proposed intermediates.
Journal of Organometallic Chemistry, 1970
The kinetics of monosubstitution reactions of Co(CO)3NO with As(C6H5)3 and P(C6H5)3 in cyclohexan... more The kinetics of monosubstitution reactions of Co(CO)3NO with As(C6H5)3 and P(C6H5)3 in cyclohexane, toluene, nitromethane, tetrahydrofuran, acetonitrile and dimethylsulfoxide fit the two-term equation v = (k1 + k′·[L])·[S], where L and S refer to the ligand and the substrate. The rate constant, k′ for the second-order process (associative with the ligand) varies over a 5-fold range with the change in the dielectric constant of the solvent. The rate constant, k1, for the first-order process changes by factor of less than 2 with the dielectric constant in the first three, non-coordinating, solvents, but in the latter three the variation is 103 times greater. This large increase is accounted for in terms of an associative intervention of the solvent in the first-order process. This interpretation is supported by the activation parameters, which are typical of a dissociative mechanism for the first three non coordinating solvents, while for the latter three they tend towards values typical of an associative mechanism.
Journal of Organometallic Chemistry, 2006
(S)-2-Pyridyl-imino-[2.2]paracyclophane ligands 1 and 2 were synthesized by a condensation reacti... more (S)-2-Pyridyl-imino-[2.2]paracyclophane ligands 1 and 2 were synthesized by a condensation reaction of 2-COR-C5H4N (1: R=H; 2: R=Me) with enantiopure (−)-S-amino-[2.2]-paracyclophane. The reactions of 1 and 2 with [Ru(η6-cymene)Cl(μ-Cl)]2 afforded complexes [Ru(η6-cymene)Cl(N,N)]X (3: N,N=1; 4: N,N=2; X-=BPh4-,PF6-,BF4-) that were completely characterized in solution. For 4PF6 the solid state structure was determined by X-ray single-crystal diffractometric studies. Two diastereoisomers [(SRu,SL) and (RRu,SL)]
Inorganica Chimica Acta, 1968
Gnu)3) and the same bidentate ligand 1,2bis(diphenylphosphino)ethane, have been studied. In all c... more Gnu)3) and the same bidentate ligand 1,2bis(diphenylphosphino)ethane, have been studied. In all cases the end product is the disubstituted chelate complex CO(CO)NOP(C~HS)KHICHZP(C~H&. For L= P(C6H5)3 and l?(OCH3).3 there are formed to an appreciable extent, at relatively low ligand-to-complex cone. ratios, also the disubstituted complexes Co-(CO)NOLr. There is good evidence that the associative reaction mechanism goes through a path involving a primary step of substrates ligand displacement, followed by chelation. Only for Co(CO)2NOP(OCH3)3, a primary step of substrate ligand displacement, followligand, again followed by chelation, is competitive with the above one. The order of reactivity for primary ligand displacement is the following: Sb(CnHs)3> CO> As(CoHs)3> P(OC6Hs)3> P(CnH5)3> P(n-CJHq);. It is interpreted on the basis of the varied basicity and polarizability of the substrate ligands, and in specific cases of their additional x-bonding ability. Steric factors do not seem to play a relevant role.
Inorganica Chimica Acta, 1967
... Following these results a kinetic mechanism has been proposed involving two competitive proce... more ... Following these results a kinetic mechanism has been proposed involving two competitive processes, first and secondorder respectively, the relative contribution of the secondorder process appearing to decrease in the order triphenylphosphine triphenylarsine triphenyl stibine. ...
Inorganica Chimica Acta, 1999
Nucleophilic substitution of iodide in the complex Fe(CO) 2 (PMe 3) 2 MeI has been studied in dic... more Nucleophilic substitution of iodide in the complex Fe(CO) 2 (PMe 3) 2 MeI has been studied in dichloromethane using a series of bromide salts with different structure and solvation: Bu 4 NBr, PPNBr or KBr complexed with a molecular receptor (18-crown-6), as well as with a chloride salt (PPNCl) for comparison purposes. The analysis of the rate constants suggests that the reaction takes place via two reaction paths. The principal path involves the free ion (Br −). The other path involves the ion pair (A + Br −) and its rate generally increases as the dissociation constant of the salt increases. The rate of this reaction has been compared with that of the isotopomerisation and it results much faster.
Inorganica Chimica Acta, 1999
Inorganica Chimica Acta, 2003
The reactions of cis ,trans-[M(CO) 2 (PMe 3) 2 CH 3 I] [M 0/Fe (1), Ru (2)] and cis ,trans ,cis-[... more The reactions of cis ,trans-[M(CO) 2 (PMe 3) 2 CH 3 I] [M 0/Fe (1), Ru (2)] and cis ,trans ,cis-[Fe(CO) 2 (PMe 3) 2 (CH 3) 2 ] (3) with B(C 6 F 5) 3 involve Me-abstraction from the metal with formation of reactive species that undergo decomposition processes. In the presence of H 2 O complex 2 reacts with B(C 6 F 5) 3 forming cis ,trans-[Ru(CO) 2 (PMe 3) 2 I(HOB(C 6 F 5) 3)] (7) that slowly transforms in cis ,trans-[Ru(CO) 2 (PMe 3) 2 I(H 2 O)] ' [(HOB(C 6 F 5) 3)] ((8), while complex 1 affords the cyclometallate complex trans-[Fe(CO)(PMe 3) 2 I(Ä/C(Me) Ã/O Ã/B(C 6 F 5) 2 Ã/OH Ã/)] (9) whose molecular structure was investigated by X-ray diffraction studies.
Inorganic Chemistry, 1974
The reaction between Fe(CO),(CH,=CHPh) and PPh, is studied in the presence of carbon monoxide (0-... more The reaction between Fe(CO),(CH,=CHPh) and PPh, is studied in the presence of carbon monoxide (0-22 atm). The effect of carbon monoxide on the rate constants and on the [Fe(COj,PPh,] /[Fe(CO),(PPh,),] ratio is observed. The resnlts indicate that the Fe(CO),(PPh,), complex is formed by reaction of PPh, with the intermediate FelCO),. This intermediate is obtained by dissociation of Fe(CO)., which is the product of the dissociation of the Fe(CO),(CH,=CHPh) complex AIC40202I
Inorganic Chemistry, 1993
The reaction of cis,trans-Fe(C0)2(PMe&MeX with carbon monoxide to give the corresponding cis,tran... more The reaction of cis,trans-Fe(C0)2(PMe&MeX with carbon monoxide to give the corresponding cis,trans-and trans,trans-acetyls has been studied in toluene for X = C1, Br, or I at various temperatures. The formation rates and the equilibrium constants of &,trans-acetyl with respect to cis,trans-methyl follow the order NCS z CN > C1> Br > I and are determined by the withdrawing power of X, while the equilibrium constants of trans,trans-acetyl as compared to cis,trans-acetyl follow the order I > Br > C1>> CN, Me and are influenced by the steric hindrance of the ligands. rrans,rrans-Fe(CO)2(PMe3)2MeI has been prepared and characterized. Its reaction rate with CO
Inorganic Chemistry, 1992
The isotopomerization of the Fe( 13 CO a )(CO b )(PMe 3 ) 2 MeI complex was studied in various so... more The isotopomerization of the Fe( 13 CO a )(CO b )(PMe 3 ) 2 MeI complex was studied in various solvents. The kinetic and thermodynamic parameters suggest that the isotopomerization proceeds via ionization of the Fe-I bond, rearrangement of the formed ion-pair, and reentry of the iodide ligand. This behavior supports a CO insertion mechanism proceeding via direct substitution of the iodide with CO and formation of an ionic intermediate
European Journal of Inorganic Chemistry, 2001
Complexes trans-[Ru(PMe3)2(CO)(COMe)(N,N)]X (N,N = diimine or diamine ligand, X− = BF4− or BPh4−)... more Complexes trans-[Ru(PMe3)2(CO)(COMe)(N,N)]X (N,N = diimine or diamine ligand, X− = BF4− or BPh4−) have been synthesized by the reaction of cis,trans-[RuI(Me)(CO)2(PMe3)2] with N,N ligands having different steric and electronic properties. The syntheses were only successful with moderately hindered ligands; in other cases, solvento complexes were formed. Some of these were isolated and characterized. The interionic structures of the aforementioned cationic complexes have been investigated in dichloromethane solution by means of 1H-NOESY and 19F{1H}-HOESY NMR experiments. The anion−cation interactions (especially for the diamine complexes) were found to be more specific than those in analogous compounds bearing aromatic N,N ligands. For the first time, we have found that the anion preferentially resides close to the N arm trans to the COMe group.
Zeitschrift für Naturforschung B, Feb 1, 1972
The Polarographie behaviour of [ (C2H5)4N] ® [Fe(CO)3NO] e has been investigated at the mercury d... more The Polarographie behaviour of [ (C2H5)4N] ® [Fe(CO)3NO] e has been investigated at the mercury dropping electrode and platinum stationary electrode. It was found that the complex displays two anodic and one cathodic waves. On the basis of the results obtained a mechanism is proposed and discussed.
Journal of Organometallic Chemistry, 1987
Abstract [Ru(CO)4PMe3] reacts with MeI to give fac-[Ru(CO)3(PMe3)(Me)I]. The latter reacts with P... more Abstract [Ru(CO)4PMe3] reacts with MeI to give fac-[Ru(CO)3(PMe3)(Me)I]. The latter reacts with PMe3 to give a mixture of the three isomers of cis-bis(trimethylphosphine)-cis-dicarbonyl acetyl iodide [Ru(CO)2(PMe3)2(COMe)I]. Decarbonylation of the mixture gives only the trans-bis(trimethylphosphine)-cis-dicarbonyl methyl iodide complex [Ru(CO)2(PMe3)2MeI], which was also prepared by oxidative addition of MeI to [Ru(CO)3(PMe3)2].
Zeitschrift für Naturforschung B, 1972
The polarographic behaviour of [(C2H5)4N] ⊕ [Fe(CO)3NO⊖] has been investigated at the mercury dro... more The polarographic behaviour of [(C2H5)4N] ⊕ [Fe(CO)3NO⊖] has been investigated at the mercury dropping electrode and platinum stationary electrode. It was found that the complex displays two anodic and one cathodic waves. On the basis of the results obtained a mechanism is proposed and discussed.
Polyhedron, 1983
The dihaptoiminoacyI complex [Fe(C0)2 (PMe3)2(q2-CMe=N-CMe3)]+ I-was obtained by reaction of [Fe(... more The dihaptoiminoacyI complex [Fe(C0)2 (PMe3)2(q2-CMe=N-CMe3)]+ I-was obtained by reaction of [Fe(CO)z(PMes)zMeI] and tertbutylisocyanide. The structure of the complex was determined by an X-ray structure analysis.
Organometallics, 1998
The reactions of complexes trans, cis-M(PMe 3) 2 (CO) 2 (Me)I (M) Fe (1a), Ru (1b)) with N,O liga... more The reactions of complexes trans, cis-M(PMe 3) 2 (CO) 2 (Me)I (M) Fe (1a), Ru (1b)) with N,O ligands [2-acetylpyridine (2-apy), 2-benzoylpyridine (2-bzpy), and 2,2′-dipyridyl ketone (2,2′-dpk)] in the presence of NaBPh 4 afford a mixture of the two possible stereoisomers trans-[M(PMe 3) 2 (CO)(COMe)(N, O)]BPh 4 having the N arm cis (A) or trans (B) to the acetyl group. The stereochemistry of the complexes was determined by 1 H NOESY NMR spectra. For all the iron complexes the major stereoisomer is B, while for ruthenium complexes it is A. When A/B mixtures are left in methylene chloride, the concentration of A increases, indicating that A and B are the thermodynamic and kinetic reaction products, respectively. Furthermore, the more basic the N,O ligands, the more B stereoisomer that forms. The solid-state structure of 4b was obtained using single-crystal X-ray diffraction. For all the complexes , the ion-pair structures and the localization of the counterion in solution with respect to the organometallic moiety were investigated by the detection of interionic contacts in the 1 H NOESY NMR spectra. Specific interactions were observed that indicate that the counterion is localized in solution in front of the face determined by PMe 3 and the two arms of the N,O ligands.
Organometallics, 2000
The molecular self-diffusion coefficients of the complexes trans-[Ru(PMe 3) 2 (CO)(COMe)(pz 2-CH ... more The molecular self-diffusion coefficients of the complexes trans-[Ru(PMe 3) 2 (CO)(COMe)(pz 2-CH 2)]BPh 4 and trans-[Ru(PMe 3) 2 (CO)(COMe)(pz 2-BH 2)] have been measured by pulsed field gradient spin-echo NMR measurements in nitromethane, chloroform, and methylene chloride as a function of concentration. By using the neutral complex as reference with the assumption that it does not undergo associative processes, clear indications of the presence of ions (in nitromethane), ion pairs (in chloroform at low concentration), and ion quadruples (in chloroform at high concentration) have been obtained.
Journal of Organometallic Chemistry, 1975
Abstract The reaction between π-(PhCHCHCOR)Fe(CO) 3 (R = H, CH 3 , Ph) and L (L = PPh 3 , AsPh 3... more Abstract The reaction between π-(PhCHCHCOR)Fe(CO) 3 (R = H, CH 3 , Ph) and L (L = PPh 3 , AsPh 3 , SbPh 3 ) in acetone occurs in two steps. The products of the first step are the π-(PhCHCHCOR)Fe(CO) 3 L complexes, which in the second step yield Fe(CO) 3 L 2 and π-(PhCHCHCOR)Fe(CO) 2 L. The kinetic results indicate that the first step is association of the substrate with the ligand. The variation of the ratio [Fe(CO) 3 L 2 ]/[π-(PhCHCHCOR)Fe(CO) 2 L] with L suggests three different reaction paths for the second step.
Journal of Organometallic Chemistry, 1972
Journal of Organometallic Chemistry, 1974
Abstract The reaction: (π-CH 2 =CHPh)Fe(CO) 4 + (2α)PPh 3 → α Fe(CO) 4 PPh 3 + (1α)Fe(CO) 3 (PP... more Abstract The reaction: (π-CH 2 =CHPh)Fe(CO) 4 + (2α)PPh 3 → α Fe(CO) 4 PPh 3 + (1α)Fe(CO) 3 (PPh 3 ) 2 + CH 2 =CHPh + (1α)CO has been studied in dichloromethane, acetone, acetonitrile, isopropyl ether and n-hexane. The kinetics indicate that the reaction mechanism is the same as that in toluene. The solvent and temperature effects on the α/1α ratio further confirm the nature of the proposed intermediates.
Journal of Organometallic Chemistry, 1970
The kinetics of monosubstitution reactions of Co(CO)3NO with As(C6H5)3 and P(C6H5)3 in cyclohexan... more The kinetics of monosubstitution reactions of Co(CO)3NO with As(C6H5)3 and P(C6H5)3 in cyclohexane, toluene, nitromethane, tetrahydrofuran, acetonitrile and dimethylsulfoxide fit the two-term equation v = (k1 + k′·[L])·[S], where L and S refer to the ligand and the substrate. The rate constant, k′ for the second-order process (associative with the ligand) varies over a 5-fold range with the change in the dielectric constant of the solvent. The rate constant, k1, for the first-order process changes by factor of less than 2 with the dielectric constant in the first three, non-coordinating, solvents, but in the latter three the variation is 103 times greater. This large increase is accounted for in terms of an associative intervention of the solvent in the first-order process. This interpretation is supported by the activation parameters, which are typical of a dissociative mechanism for the first three non coordinating solvents, while for the latter three they tend towards values typical of an associative mechanism.
Journal of Organometallic Chemistry, 2006
(S)-2-Pyridyl-imino-[2.2]paracyclophane ligands 1 and 2 were synthesized by a condensation reacti... more (S)-2-Pyridyl-imino-[2.2]paracyclophane ligands 1 and 2 were synthesized by a condensation reaction of 2-COR-C5H4N (1: R=H; 2: R=Me) with enantiopure (−)-S-amino-[2.2]-paracyclophane. The reactions of 1 and 2 with [Ru(η6-cymene)Cl(μ-Cl)]2 afforded complexes [Ru(η6-cymene)Cl(N,N)]X (3: N,N=1; 4: N,N=2; X-=BPh4-,PF6-,BF4-) that were completely characterized in solution. For 4PF6 the solid state structure was determined by X-ray single-crystal diffractometric studies. Two diastereoisomers [(SRu,SL) and (RRu,SL)]
Inorganica Chimica Acta, 1968
Gnu)3) and the same bidentate ligand 1,2bis(diphenylphosphino)ethane, have been studied. In all c... more Gnu)3) and the same bidentate ligand 1,2bis(diphenylphosphino)ethane, have been studied. In all cases the end product is the disubstituted chelate complex CO(CO)NOP(C~HS)KHICHZP(C~H&. For L= P(C6H5)3 and l?(OCH3).3 there are formed to an appreciable extent, at relatively low ligand-to-complex cone. ratios, also the disubstituted complexes Co-(CO)NOLr. There is good evidence that the associative reaction mechanism goes through a path involving a primary step of substrates ligand displacement, followed by chelation. Only for Co(CO)2NOP(OCH3)3, a primary step of substrate ligand displacement, followligand, again followed by chelation, is competitive with the above one. The order of reactivity for primary ligand displacement is the following: Sb(CnHs)3> CO> As(CoHs)3> P(OC6Hs)3> P(CnH5)3> P(n-CJHq);. It is interpreted on the basis of the varied basicity and polarizability of the substrate ligands, and in specific cases of their additional x-bonding ability. Steric factors do not seem to play a relevant role.
Inorganica Chimica Acta, 1967
... Following these results a kinetic mechanism has been proposed involving two competitive proce... more ... Following these results a kinetic mechanism has been proposed involving two competitive processes, first and secondorder respectively, the relative contribution of the secondorder process appearing to decrease in the order triphenylphosphine triphenylarsine triphenyl stibine. ...
Inorganica Chimica Acta, 1999
Nucleophilic substitution of iodide in the complex Fe(CO) 2 (PMe 3) 2 MeI has been studied in dic... more Nucleophilic substitution of iodide in the complex Fe(CO) 2 (PMe 3) 2 MeI has been studied in dichloromethane using a series of bromide salts with different structure and solvation: Bu 4 NBr, PPNBr or KBr complexed with a molecular receptor (18-crown-6), as well as with a chloride salt (PPNCl) for comparison purposes. The analysis of the rate constants suggests that the reaction takes place via two reaction paths. The principal path involves the free ion (Br −). The other path involves the ion pair (A + Br −) and its rate generally increases as the dissociation constant of the salt increases. The rate of this reaction has been compared with that of the isotopomerisation and it results much faster.
Inorganica Chimica Acta, 1999
Inorganica Chimica Acta, 2003
The reactions of cis ,trans-[M(CO) 2 (PMe 3) 2 CH 3 I] [M 0/Fe (1), Ru (2)] and cis ,trans ,cis-[... more The reactions of cis ,trans-[M(CO) 2 (PMe 3) 2 CH 3 I] [M 0/Fe (1), Ru (2)] and cis ,trans ,cis-[Fe(CO) 2 (PMe 3) 2 (CH 3) 2 ] (3) with B(C 6 F 5) 3 involve Me-abstraction from the metal with formation of reactive species that undergo decomposition processes. In the presence of H 2 O complex 2 reacts with B(C 6 F 5) 3 forming cis ,trans-[Ru(CO) 2 (PMe 3) 2 I(HOB(C 6 F 5) 3)] (7) that slowly transforms in cis ,trans-[Ru(CO) 2 (PMe 3) 2 I(H 2 O)] ' [(HOB(C 6 F 5) 3)] ((8), while complex 1 affords the cyclometallate complex trans-[Fe(CO)(PMe 3) 2 I(Ä/C(Me) Ã/O Ã/B(C 6 F 5) 2 Ã/OH Ã/)] (9) whose molecular structure was investigated by X-ray diffraction studies.
Inorganic Chemistry, 1974
The reaction between Fe(CO),(CH,=CHPh) and PPh, is studied in the presence of carbon monoxide (0-... more The reaction between Fe(CO),(CH,=CHPh) and PPh, is studied in the presence of carbon monoxide (0-22 atm). The effect of carbon monoxide on the rate constants and on the [Fe(COj,PPh,] /[Fe(CO),(PPh,),] ratio is observed. The resnlts indicate that the Fe(CO),(PPh,), complex is formed by reaction of PPh, with the intermediate FelCO),. This intermediate is obtained by dissociation of Fe(CO)., which is the product of the dissociation of the Fe(CO),(CH,=CHPh) complex AIC40202I
Inorganic Chemistry, 1993
The reaction of cis,trans-Fe(C0)2(PMe&MeX with carbon monoxide to give the corresponding cis,tran... more The reaction of cis,trans-Fe(C0)2(PMe&MeX with carbon monoxide to give the corresponding cis,trans-and trans,trans-acetyls has been studied in toluene for X = C1, Br, or I at various temperatures. The formation rates and the equilibrium constants of &,trans-acetyl with respect to cis,trans-methyl follow the order NCS z CN > C1> Br > I and are determined by the withdrawing power of X, while the equilibrium constants of trans,trans-acetyl as compared to cis,trans-acetyl follow the order I > Br > C1>> CN, Me and are influenced by the steric hindrance of the ligands. rrans,rrans-Fe(CO)2(PMe3)2MeI has been prepared and characterized. Its reaction rate with CO
Inorganic Chemistry, 1992
The isotopomerization of the Fe( 13 CO a )(CO b )(PMe 3 ) 2 MeI complex was studied in various so... more The isotopomerization of the Fe( 13 CO a )(CO b )(PMe 3 ) 2 MeI complex was studied in various solvents. The kinetic and thermodynamic parameters suggest that the isotopomerization proceeds via ionization of the Fe-I bond, rearrangement of the formed ion-pair, and reentry of the iodide ligand. This behavior supports a CO insertion mechanism proceeding via direct substitution of the iodide with CO and formation of an ionic intermediate
European Journal of Inorganic Chemistry, 2001
Complexes trans-[Ru(PMe3)2(CO)(COMe)(N,N)]X (N,N = diimine or diamine ligand, X− = BF4− or BPh4−)... more Complexes trans-[Ru(PMe3)2(CO)(COMe)(N,N)]X (N,N = diimine or diamine ligand, X− = BF4− or BPh4−) have been synthesized by the reaction of cis,trans-[RuI(Me)(CO)2(PMe3)2] with N,N ligands having different steric and electronic properties. The syntheses were only successful with moderately hindered ligands; in other cases, solvento complexes were formed. Some of these were isolated and characterized. The interionic structures of the aforementioned cationic complexes have been investigated in dichloromethane solution by means of 1H-NOESY and 19F{1H}-HOESY NMR experiments. The anion−cation interactions (especially for the diamine complexes) were found to be more specific than those in analogous compounds bearing aromatic N,N ligands. For the first time, we have found that the anion preferentially resides close to the N arm trans to the COMe group.
Zeitschrift für Naturforschung B, Feb 1, 1972
The Polarographie behaviour of [ (C2H5)4N] ® [Fe(CO)3NO] e has been investigated at the mercury d... more The Polarographie behaviour of [ (C2H5)4N] ® [Fe(CO)3NO] e has been investigated at the mercury dropping electrode and platinum stationary electrode. It was found that the complex displays two anodic and one cathodic waves. On the basis of the results obtained a mechanism is proposed and discussed.
Journal of Organometallic Chemistry, 1987
Abstract [Ru(CO)4PMe3] reacts with MeI to give fac-[Ru(CO)3(PMe3)(Me)I]. The latter reacts with P... more Abstract [Ru(CO)4PMe3] reacts with MeI to give fac-[Ru(CO)3(PMe3)(Me)I]. The latter reacts with PMe3 to give a mixture of the three isomers of cis-bis(trimethylphosphine)-cis-dicarbonyl acetyl iodide [Ru(CO)2(PMe3)2(COMe)I]. Decarbonylation of the mixture gives only the trans-bis(trimethylphosphine)-cis-dicarbonyl methyl iodide complex [Ru(CO)2(PMe3)2MeI], which was also prepared by oxidative addition of MeI to [Ru(CO)3(PMe3)2].