Raúl Contreras

Bis(diphenylphosphino)amine and their dichalcogenide derivatives as ligands in rhodium(III), iridium(III), and ruthenium(II) complexes. Crystal structures of [(η5-C5Me5)MCl{η2-(SePPh2)2N}] (M=Rh, Ir)

Abstract Reaction of the dimers [{(η 5 -C 5 Me 5 )MCl} 2 (μ-Cl) 2 ] (M=Rh, Ir) or [{(η 6 -arene)RuCl} 2 (μ-Cl) 2 ] (arene= p -MeC 6 H 4 i Pr, C 6 Me 6 ) with NH(PPh 2 ) 2 in the presence of AgA (A=BF 4 , PF 6 ) leads to the mononuclear cationic complexes [(η 5 -C 5 Me 5 )MCl{η 2 -(PPh 2 ) 2 NH}]A (M=Rh ( 1 ), Ir ( 2 )) or [(η 6 -arene)RuCl{η 2 -(PPh 2 ) 2 NH}]A (arene= p -MeC 6 H 4 i Pr ( 3 ), C 6 Me 6 ( 4 )). Similar reactions using the chalcogenide derivatives NH(EPPh 2 ) 2 (E=S, Se) yield the neutral complexes [(η 5 -C 5 Me 5 )RhCl{η 2 -(EPPh 2 ) 2 N}] (E=S ( 5 ), Se ( 6 )), [(η 5 -C 5 Me 5 )IrCl{η 2 -(EPPh 2 ) 2 N}] (E=S ( 7 ), Se ( 8 )), [(η 6 -arene)RuCl{η 2 -(SPPh 2 ) 2 N}] (arene=C 6 H 6 ( 9 ), p -MeC 6 H 4 i Pr ( 10 )) and [(η 6 -arene)RuCl{η 2 -(SePPh 2 ) 2 N}] (arene=C 6 Me 6 ( 11 ), p -MeC 6 H 4 i Pr ( 12 )). Chloride abstraction from complexes 5 – 8 with AgPF 6 in the presence of PPh 3 gives the cationic complexes [(η 5 -C 5 Me 5 )Rh{η 2 -(EPPh 2 ) 2 N}(PPh 3 )]PF 6 (E=S ( 13 ), Se ( 14 )) and [(η 5 -C 5 Me 5 )Ir{η 2 -(EPPh 2 ) 2 N}(PPh 3 )]PF 6 (E=S ( 15 ), Se ( 16 )). Complexes 13 – 16 can also be synthesised from the starting dinuclear complexes, AgPF 6 , NH(EPPh 2 ) 2 and PPh 3 . Using this alternative synthetic route the related ruthenium complexes [(η 6 -C 6 Me 6 )Ru{η 2 -(EPPh 2 ) 2 N}(C 5 H 5 N)] BF 4 (E=S ( 17 ), Se ( 18 )) can be prepared. All described compounds have been characterised by microanalysis and NMR ( 1 H, 31 P) and IR spectroscopy. The crystal structures of the neutral complexes [(η 5 -C 5 Me 5 )MCl{η 2 -(SePPh 2 ) 2 N}] (M=Rh ( 6 ), Ir ( 8 )) have been determined by X-ray diffraction methods. Both complexes exhibit analogous pseudo-octahedral molecular structures with a C 5 Me 5 group occupying three coordination positions and a bidentate chelate Se,Se′-bonded ligand and a chloride atom completing the coordination sphere.

Bis(diphenylphosphino)methane and its sulphide or selenide derivatives as ligands in ruthenium(II) and rhodium(III) complexes: Crystal structure of [(η6C6Me6)Ru{η3(SPPh2)2CH}]ClO4

Abstract Reaction of complexes [( η 6 C 6 Me 6 )RuCl 2 ] 2 and [( η 5 C 5 Me 5 )RhCl 2 ] 2 with the ligands L  Ph 2 PCH 2 PPh 2 (dppm) or Ph 2 PCH 2 P(Se)Ph 2 in benzene solutions led to neutral complexes with the general formula [(ring)MCl 2 ( η 1 L)]. The reactivity of the uncoordinated P atom of dppm has been studied. When the reaction was carried out in methanol solutions, cationic complexes, with the ligands acting in their bidentate form, were obtained. Similar cationic perchlorate complexes were prepared using acetone as solvent in the presence of sodium perchlorate, yielding [(ring)MCl( η 2 L)ClO 4 , where L  Ph 2 PCH 2 PPh 2 , Ph 2 PCH 2 P(Se)Ph 2 or Ph 2 P(S)CH 2 P(S)Ph 2 . The complex [( η 6 C 6 Me 6 )RuCl{ η 2 (SPPh) 2 CH 2 -S,S′}]ClO 4 reacted with sodium hydride in tetrahydrofuran or thallium pyrazolate in dichloromethane solution by deprotonation of the coordinated bidentate ligand giving the complex [( η 6 C 6 Me 6 )Ru{ η 3 (SPPh 2 ) 2 CH-C,S,S′}]ClO 4 . The structure of this compl has been determined by single crystal X-ray diffraction methods. The complex contains a tridentate C,S,S′-bonded ligand occupying three coordination positions of a distorted octahedral ruthenium centre, with an η 6 C 6 Me 6 group completing the coordination sphere.

New coordination mode of bis(diphenylphosphine) methanide diselenide. Synthesis and X-ray crystal structure of [(η5 C5Me5)Rh{η3 (SePPh2)2CH&}]ClO4

Abstract The dinuclear complexes [(η5 C5Me5)RhCl2]2 and [(η6 C6Me6)RuCl2]2 reacted with dppmSe2 giving the cationic compounds [(η5 C5Me5)RhCl{η2 (SePPh2)2CH2&}]+ (1) and [(η6 C6Me6)RuCl{η2 (SePPh2)2CH2&}]+ (2), which were isolated as perchlorate salts. Deprotonation reactions of these compounds yielded the new complexes [(η5 C5Me5)Rh{η3 (SePPh2)2CH&}]ClO4 (3) and [(η6 C6Me6)Ru{η3 (SePPh2)2CH&}]ClO4 (4), respectively, in which the anionic methanide diselenide ligand is acting as a tripod ligand, with a C,Se,Se′-donor set. The structure of3 has been determined by X-ray crystallography.

Synthesis and characterization of heterodinuclear RuPt and IrPt complexes containing pyrazolate bridging ligands. Crystal structure of [(η5-C5Me5)Ir(μ-pz)3PtMe3] (pz=pyrazolate)

The reaction of the metallo–ligand [Ru(η 6 - p -cymene)(pz) 2 (Hpz)] with the platinum complex [{PtIMe 3 } 4 ] affords mixtures of the heterodinuclear complexes [(η 6 - p -cymene)Ru(μ-pz) 3 PtMe 3 ] ( 1 ) and [(η 6 - p -cymene)Ru(μ-pz) 2 (μ-I)PtMe 3 ] ( 2 ). The reaction of the iridium derivative [Ir(η 5 -C 5 Me 5 )(pz) 2 (Hpz)] with [{PtIMe 3 } 4 ] gives [(η 5 -C 5 Me 5 )Ir(μ-pz) 2 (μ-I)PtMe 3 ] ( 3 ). Both [Ru(η 6 - p -cymene)(pz) 2 (Hpz)] and [Ir(η 5 -C 5 Me 5 )(pz) 2 (Hpz)] react with [{PtIMe 3 } 4 ] in the presence of NaOH yielding 1 and [(η 5 -C 5 Me 5 )Ir(μ-pz) 3 PtMe 3 ] ( 4 ), respectively. While [Ru(η 6 - p -cymene)(pz) 2 (Hpz)] reacts with [PtBr 2 Me 2 S x ] to give mixtures of [(η 6 - p -cymene)Ru(μ-pz) 3 PtBrMe 2 ] ( 5 ) and [(η 6 - p -cymene)Ru(μ-pz) 2 (μ-Br)PtBrMe 2 ] ( 6 ), the reaction of [Ir(η 5 -C 5 Me 5 )(pz) 2 (Hpz)] with [PtBr 2 Me 2 S x ] gives [(η 5 -C 5 Me 5 )Ir(μ-pz) 2 (μ-Br)PtBrMe 2 ] ( 7 ) as the sole product. All species were characterized in solution by 1 H-NMR spectroscopy. The crystal structure of complex 4 has been determined by single-crystal X-ray diffraction.

Diphenylphosphino(phenylthio)methane as a monodentate or bidentate chelate ligand in rhodium, iridium and ruthenium complexes, 3rystal structure of [(η5-C5Me5) IrCl(η2-Ph2PCH2SPhP,S)]BF4·Me2CO

Abstract Reactions of complexes [∗(η 5 - C 5 Me 5 ) MCl 2 ∗ 2 ] ( M = Rh, Ir ) and [∗(η 6 - MeC 6 H 4 Pr i ) RuCl 2 ∗ 2 ] with the ligand Ph2PCH2SPh in acetone solution led to neutral complexes with the general formula [(ring)MCl2(η1-Ph2PCH2SPhP)] (1–3). These compounds react with thallium tetrafluoroborate in acetone solution to yield new cationic complexes in which the ligand is acting in its chelate P,S-donor fashion, [(ring)MCl(η2-Ph2PCH2SPhP,S)]BF4 (4–6). When the removal of the chloride ligand in complexes 1–3 was carried out in the presence of a stoichiometric amount of Ph2PCH2SPh, cationic compounds containing two P-donor monodentate ligands of the type [(η5-C5Me5)MCl (η1-Ph2PCH2SPhP)2]BF4 (7 and 8) were obtained. The structure of the iridium derivative [(η5-C5Me5)IrCl(η2-Ph2PCH2SPhP,S)]BF4 · Me2CO has been determined by single-crystal X-ray diffraction methods. The complex cation contains a C5Me5 group occupying three coordination positions of a distorted octahedral iridium centre, a bidentate chelate P,S-bonded ligand and a chloride atom completing the coordination sphere.

Pentamethylcyclopentadienyliridium(III) complexes containing tertiary phosphorus chalcogenide ligands: crystal structure of [(η5C5Me5)Ir{PO(OMe)2}{η2(SPPh2)2CH2S, S′}] BF4 · 0.5Me2CO

Abstract Neutral iridium(III) complexes of the unidentate P-donor ligands dppm, dppmS and dppmSe, and cationic complexes with these ligands acting in their bidentate form have prepared and characterized. Similar cationic complexes with the symmetrical bidentate dichalcogenide ligands dppmS 2 and dppmSe 2 have been described. These compounds react with sodium hydride in tetrahydrofuran or with thallium pyrazolate in dichloromethane to yield the new cationic complexes [( η 5 C 5 Me 5 )Ir{ η 3 (EPPh 2 ) 2 CHC,E,E′}] + (E = S, Se) in which the anionic methanide dichalcogenide ligand is acting as a tripod ligand with a C,E,E′-donor set. However, the complexes [( η 5 C 5 Me 5 )IrCl( η 2 dppmE 2 )]BF 4 react with P(OMe) 3 in the presence of TIBF 4 , to give the dicationic compounds [( η 5 C 5 Me 5 )Ir{P(OMe) 3 }( η 2 dppmE 2 )](BF 4 ) 2 . In these complexes, the P(MOe) 3 l is transformed into a coordinated PO(OMe) 2 group by reaction with sodium iodide in acetone. the structure of the complex [( η 5 C 5 Me 5 )Ir{PO(OMe) 2 }( η 2 dppmS 2 S,S′)]BF 4 · 0.5Me 2 CO have been determined by single crystal X-ray diffraction methods.

Synthesis of transition-metal complexes with heterodifunctional ligands derived of NH(PPh2)2. Crystal structure of [(η5-C5Me5)RhCl{η2-P,Se-Ph2PNP(Se)Ph2}]·CH2Cl2

The uncoordinated P atom of the bis(diphenylphosphine)amine (dppa) ligand in complexes [(ring)MCl 2 (η 1 - P -PPh 2 NHPPh 2 )] (M=Rh, Ir, Ru) reacts with sulphur or selenium to form [(ring)MCl 2 (η 1 - P -PPh 2 NHP(E)Ph 2 )] (E=S ( 1 – 3 ), Se ( 4 – 6 )) containing the P-coordinated monosulphide or monoselenide ligands. The selenium derivatives have also been directly prepared from the corresponding [{(ring)MCl 2 } 2 ] dimer and dppaSe. Chloride abstraction from rhodium and ruthenium complexes gives the neutral compounds [(ring)MCl(η 2 - P , E -PPh 2 NP(E)Ph 2 )] ( 7 – 10 ) whilst the iridium derivatives yield cationic complexes of the general formula [{η 5 -C 5 Me 5 )IrCl(η 2 - P , E -PPh 2 NHP(E)Ph 2 )] + ( 11 and 12 ). The crystal structure of complex [(η 5 -C 5 Me 5 )RhCl{η 2 - P , Se -PPh 2 NP(Se)Ph 2 }] has been established by X-ray crystallography. The rhodium atom exhibits a distorted octahedral coordination with a η 5 -C 5 Me 5 group occupying the centre of three octahedral sites; a bidentate chelate P,Se-bonded ligand and a chloride atom complete the metal coordination sphere.

Dithioethers as ligands in pentamethylcyclopentadienylrhodium(III) and iridium(III) complexes. Crystal structures of [{(η5-C5Me5)Rh}2(μ-Cl)2{μ-(MeS)2CH2}](BF4)2·H2O and [(η5-C5Me5)IrCl2{η1-(PhS)2CH2}]

Reactions of complexes [{(η 5 -C 5 Me 5 )MCl 2 } 2 ] (M=Rh, Ir) with the ligand (MeS) 2 CH 2 in CH 2 Cl 2 solution led to the neutral dinuclear complexes of the general formula [{(η 5 -C 5 Me 5 )MCl 2 } 2 {μ-(MeS) 2 CH 2 }] [M=Rh ( 1 ), Ir ( 2 )]. Compound 1 reacts in CH 2 Cl 2 solution with silver tetrafluoroborate in 1:2 molar ratio to yield the dinuclear cationic complex [{(η 5 -C 5 Me 5 )Rh} 2 (μ-Cl) 2 {μ-(MeS) 2 CH 2 }](BF 4 ) 2 ·H 2 O ( 3 ). Compound 2 reacts with silver salts in analogous conditions to give the mononuclear cationic complex [(η 5 -C 5 Me 5 )IrCl{η 2 -(MeS) 2 CH 2 }]BF 4 ( 4 ). Reactions of the starting complexes [{(η 5 -C 5 Me 5 )MCl 2 } 2 ] with the ligand (PhS) 2 CH 2 afforded the mononuclear complexes [(η 5 -C 5 Me 5 )MCl 2 (η 1 -(PhS) 2 CH 2 )] [M=Rh ( 5 ), Ir ( 6 )]. All the complexes have been characterised by analytical and spectroscopic means, and the fluxional behaviour of 4 , in solution, has been studied. The crystal structures of complexes 3 and 6 have been established by X-ray crystallography. Complex 3 crystallised in space group P 2 1 / n , a =11.848(2), b =12.693(2), c =21.608(4) A, β =95.18(2)° and Z =4. The complex cation consists of two (η 5 -C 5 Me 5 )Rh moieties connected by two chloride atoms and one dithioether group. The two rhodium atoms are separated by 3.6093(10) A. Complex 6 crystallised in space group P 2 1 / c , a =8.366(1), b =16.011(3), c =17.911(2) A, β =100.28(1)° and Z =4. The iridium atom has a distorted octahedral co-ordination with a η 5 -C 5 Me 5 group occupying the centre of three octahedral sites, two chloride atoms and a sulphur of a monodentate bis(phenylthio)methane ligand.

Synthesis and electrochemical properties of p-cymene-ruthenium(II) complexes with (EPPh2)2CHR (ES, Se; RH, Me) and their anionic derivatives as ligands. Crystal structure of [(η6-MeC6H4Pri)Ru{η3-(SPPh2)2CMe-C,S,S′}]PF6

Abstract The synthesis and properties of cationic complexes of general formula [(η6-MeC6H4Pri)RuCl{η2-EPPh2)2CHR-E,E′})]BF4 (RH, ES (1), Se (2); RMe, ES (5)) are described. The methylene proton of the coordinated dichalcogenide ligand reacts with strong bases such as KOH in methanol or TIPz in dichloromethane solutions, to give new cationic complexes in which the anionic ligand is acting as tridentate chelate with a C,E,E′-donor set. [(η6-MeC6H4Pri)Ru{η3-(EPPh2)2CR-C,E,E′ })]A (RH, A BF4−, ES (3), Se (4); RMe, APF6−, ES (6)). The complexes have been characterised by elemental analyses, molar conductivities and IR and NMR spectroscopy. The structure of the title complex was established by X-ray crystallography. The crystals are tetragonal; at 293°Ca = 15.120(2), c = 16.090(3)A, space group P43, Z = 4. The complex contains a tridentate C,S,S′-bonded ligand occupying three coordination positions of a distorted octahedral ruthenium centre, with an η6-MeC6H4Pri group completing the coordination sphere. Cyclic voltammetry shows that under argon the acidic protons of the coordinated neutral disulfide ligands (1.5) are reduced to hydrogen yielding the complexes with the anionic ligand coordinated in their tridentate form (3,6). These compounds are irreversible reduced in one-electron process to give Ru(1) species, followed by chemical decomposition.

Platinum(II) complexes with dithiolates and phosphinites as ligands: crystal structure of [Pt{S2CO}{P(OMe)Ph2}2]

Abstract Reaction of the complex [PtCl{P(O)Ph2}{P(OH)Ph2}2] with silver or thallium derivatives of dithiolate ligands led to neutral complexes of general formula [Pt{S-S}{P(O)Ph2}{P(OH)Ph2}], where { SS } − = { S 2 CNEt 2 } − { S 2 P(OEt) 2 } − ( 2 ) and { S 2 COEt } − ( 3 ) . Complexes 2 and 3 reacted with an excess of NaI in acetone solution by dealkylation of the coordinated dithiolate ligand and formation of the compounds [Pt{S2P(O)(OEt)}{P(O)Ph2}{P(OH)Ph2}]Na (4) and [Pt{S2CO}{P(O)Ph2}{P(OH)P Na (5), respectively. The corresponding tetraphenylphosphonium derivatives (6, 7) were prepared by a metathetical reaction of these complexes with Ph4PBr in acetone solution. Related dithiolate complexes were obtained by reaction of the complex [Pt{S-S}2] with P(OMe)Ph2 in molar ratio 1 : 2. Thus, the reaction of [Pt{S2COEt}2] in dichloromethane solution at room temperature gave [Pt{S2COEt}{P(OMe)Ph2}2]Cl (8). This complex reacted with NaI in acetone to form the neutral compound [Pt{S2CO}{P(OMe)Ph2}2] (9). When the reaction was carried out in dichloromethane at reflux temperature using [Pt{S2P(OEt)2}2] as starting material, the neutral compound [Pt{S2P(O)(OEt)} {P(OMe)Ph2}2] (10) was obtained. The crystal structure of the complex 9 has been determined by X-ray diffraction. The neutral complex shows a nearly square-planar coordination of the metal and a planar dithiocarbonate ligand.