Joan Suades

Metal complexes of mercaptoamines—III. Different behaviour of β- and γ-(N,N-dimethyl)-mercaptoamines

Abstract The complexes Ni6(MPDMA)12, [Ni6(MPDMAH)12]X12 X = (I, ClO4) and Pd2(MPDMA)2Cl2 (MPDMA = t-S(CH2)3N(CH3)2) have been prepared and characterized. An X-ray diffraction study shows that the structure of [Ni6(MPDMAH)12] (ClO4)12 consists of a cyclic hexanuclear array of nickel atoms linked by sulphur bridging ligands. Infrared and electronic spectra show that there is no chelation in any of the nickel complexes. However, coordination through the nitrogen atoms occurs in the palladium complex. This behaviour differs from that of the homologous β-mercaptoamine, which forms monomeric chelate complexes with both nickel and palladium.

Hydridorhodium(I) complexes with amphiphilic polyether phosphines: NMR study and biphasic hydroformylation of 1-octene

Abstract The formation of hydridorhodium(I) complexes with the amphiphilic phosphines 4-(R)C 6 H 4 (OCH 2 CH 2 ) n PPh 2 (R=2,2,4,4-tetramethylbutyl, n =1, n =5 ) was studied by NMR methods and IR spectroscopy. Two approaches were used: (1) the substitution reaction of triphenylphosphine in RhH(CO)(PPh 3 ) 3 by an amphiphilic phosphine and (2) a reaction between the precursor Rh(acac)(CO) 2 , syngas and the amphiphilic ligand in hydroformylation reaction conditions. Both approaches show the formation of P-coordinated hydridorhodium(I) complexes, and no relevant chelated (P, O) complexes were recognised. The biphasic rhodium-catalysed hydroformylation of 1-octene with the following water-soluble amphiphilic phosphines was studied: 4-(R)C 6 H 4 (OCH 2 CH 2 ) n P(Ph)CH 2 CH 2 SO 3 Na (R=2,2,4,4-tetramethylbutyl, n =1.4,5.1,11.2 ; R= n -nonyl, n =1.6,5.6,11.4 ), and RP(Ph)CH 2 CH 2 SO 3 Na (R= n -octyl, CH 3 (OCH 2 CH 2 ) 2 OCH 2 CH 2 ). Ligands with a hydrophobic group and a short polyether chain led to the higher conversion. This result is ascribed to the ability of these ligands to increase the metal concentration in the organic phase.

New Surfactant Phosphine Ligands and Platinum(II) Metallosurfactants. Influence of Metal Coordination on the Critical Micelle Concentration and Aggregation Properties

We have prepared the first platinum(II) metallosurfactants from a new family of linear surfactant phosphines Ph(2)P(CH(2))(n)SO(3)Na {1 (n = 2), 2 (n = 6), and 3 (n = 10)}, which were synthesized by reaction between the halosulfonates X(CH(2))(n)SO(3)Na and sodium diphenylphosphide. The metallosurfactants cis-[PtCl(2)L(2)] (L = 1-3) were obtained after reaction between the phosphines and PtCl(2) in dimethylsulfoxide. All compounds were fully characterized by the usual methods {NMR ((1)H, (13)C, (31)P, (195)Pt), IR, MS-ESI and HRMS}. By exploring the surfactant properties of phosphines 1-3 and their respective platinum metallosurfactants cis-[PtCl(2)L(2)] (L = 1-3) through surface tension measurements, dynamic light scattering spectroscopy, and cryo-TEM microscopy, we were able to analyze the influence of the metal coordination on the critical micelle concentration (cmc) and the aggregation properties. The cmc values of platinum metallosurfactants were considerably lower than those obtained for the free phosphines 1-3. This behavior could be understood by an analogy between the structure of cis-[PtCl(2)L(2)] complexes and bolaform surfactants. The calculated values of area per molecule also showed different tendencies between 1-3 and cis-[PtCl(2)L(2)] complexes, which could be explained on the basis of the possible conformations of these compounds in the air-water interface. The study of aggregates by dynamic light scattering spectroscopy and cryo-TEM microscopy showed the formation of spherical disperse medium size vesicles in all cases. However, substantial differences were observed between the three free phosphines (the population of micellar aggregates increased with long chain length) and also between phosphines and their respective metallosurfactants.

Usefulness of 99mTc-ciprofloxacin scintigraphy in the diagnosis of prosthetic joint infections.

ObjectiveTo evaluate the usefulness of 99mTc-ciprofloxacin scintigraphy (CFS) in patients with hip or knee arthroplasty and suspected infection. MethodsForty patients (26 women, 14 men) with a mean age of 66±10 years and local pain in the hip (21), knee (16), or shoulder (three) prosthesis were recruited. CFS was performed at 1, 4, and 24 h after intravenous injection of 370 MBq. Anterior and posterior views centered on the affected joint were performed in all patients. A routine bone scan, 99mTc-hexamethylpropyleneamine oxime leukocyte scan, and 99mTc-colloid scan [leukocyte scintigraphy–bone marrow scintigraphy (LS–MS)] were performed. Final diagnosis of infection was confirmed by positive microbiological analysis or macroscopic evidence of purulent material. ResultsDiagnosis of arthroplasty infection was established in 16 out 40 cases: coagulase-negative staphylococci (nine), Staphylococcus aureus (three), Enterococcus (one), and macroscopic infection in the remaining three cases. CFS imaging showed the 24-h image to be the best acquisition time-point. The sensitivity, specificity, negative predictive value, and positive predictive value for LS–MS were 75, 92, 86, and 85%, whereas for CFS at 24 h these figures were 88, 71, 67, and 89%. The sensitivity and specificity for LS–MS and for CFS at 24 h for hip were (74, 90, and 88, 85%) and for knee (83, 90 and 100, 50%). ConclusionCFS can be useful in the diagnosis of arthroplasty infection of the hip as a substitute for LS–MS. It is recommended that CFS images be obtained 24 h after injection. The lack of specificity of CFS makes this technique inadequate for knee prostheses in this series.

Cationic molybdenum complexes with P-coordinated (diphenylphosphino)alkynes

Abstract New cationic P-coordinated (diphenylphosphino)alkyne complexes with molybdenum [(Mp)Ph2PCCR][BF4] {R=H, Me, tBu, Ph, Tol; Mp=(C5H5)Mo(CO)3} have been prepared from reaction between a (diphenylphosphino)alkyne Ph2PCCR and the dinuclear complex [(C5H5)Mo(CO)3]2, with Ag(I) as oxidant. The bis(diphenyphosphosphino)acetylene Ph2PCCPPh2 led to the following homo- and heteronuclear metal complexes by the same method: [(Mp)Ph2PCCPPh2][BF4], [(Mp)Ph2PCCPPh2(Mp)][BF4]2 and [(Mp)Ph2PCCPPh2(Fp)][BF4]2 {Fp=(C5H5)Fe(CO)2}. The reaction of the P-coordinated molybdenum complexes [(Mp)Ph2PCCR][BF4] with dicobalt octacarbonyl at room temperature afforded the cationic heterometallic complexes [(Mp)Ph2PC2R{Co2(CO)6}][BF4]. All complexes were characterised by microanalysis and IR, 1H-, 13C- and 31P-NMR spectroscopy.

REACTIONS OF CATIONIC IRON P-COORDINATED (DIPHENYLPHOSPHINO) ALKYNES WITH DICOBALT OCTACARBONYL

Reaction of the P-coordinated transition metal complexes [(Fp)Ph(2)PC=CR][BF4] (R = H, CH3, Ph, p-tolyl; Fp = CpFe(CO)(2)) with cobalt octacarbonyl at room temperature affords the cationic heterometallic complexes [(Fp)Ph(2)PC=CR{Co-2(CO)(6)}][BF4] (1-4) in high yields. A single-crystal X-ray structural analysis of 3 showed that the hexacarbonyldicobalt fragment is rr-bonded to the alkynyl group of the P-coordinated (diphenylphosphino)alkyne without significant interaction between the iron and cobalt fragments. Spectroscopic data for 1-4 and structural data for 3 suggest that the positive charge is mainly located on the iron fragment.

Metal complexes of mercaptoamines. II: New assignment of the structure of bis(β-mercaptoethylamine) nickel (II) and related compounds

Abstract A cis-geometry was proposed for the green complex bis(β-mercaptoethylamine) nickel(II) on the basis of its reactivity, IR spectroscopy and orbital geometry considerations. The crystal and molecular structure of this complex has been determined by X-ray diffraction and shows that the complex has a trans geometry. The crystal structure consists of trans-NiL2 molecules strongly linked through NH-S hydrogen bonds. Electronic and IR spectroscopy, and powder X-ray analysis are in agreement with the same trans geometry for the complexes bis(β-mercaptoethylamine)palladium(II) and bis-(γ-mercaptopropylamine)nickel(II). As a result of the new assignment of the structure of these complexes some concepts, such as its reactivity with nickel(II), are reconsidered.

OCTAHEDRAL TRINUCLEAR COMPLEXES WITH AMINOTHIOLATES. CRYSTAL STRUCTURE OF HEXAKIS(3-AMINO-1-PROPANETHIOLATE)TRICOBALT(III) CHLORIDE

Abstract The crystal structure of the complex {Co 3 [S(CH 2 ) 3 NH 2 ] 6 }Cl 3 was determined by X-ray diffraction methods. It is composed of discrete trinuclear cation and chloride anions linked by NH…Cl hydrogen bonds. All the ligands are chelated to metal atoms, and the cation can be described as being formed by three octahedra sharing two opposite faces. Electronic spectroscopy indicates that the structure of the complex {Co 3 [S(CH 2 ) 2 NH 2 ] 6 }Cl 3 should be very similar. The homologous iron(III) complexes {Fe 3 [S(CH 2 ) 3 NH 2 ] 6 }Cl 3 and {Fe 3 [S(CH 2 ) 2 NH 2 ] 6 }Cl 3 were synthesized and their infrared spectra show that the same structure could be considered for these complexes.

Reactivity of [HFe3(CO)11]−1 toward alkynes: II. Reactions with monosubstituted alkynes: from alkylidyne to acetylide ligands on a triiron unit

Abstract The reactions of monosubstituted alkynes (RCCH (R = C 6 H 5 , C 3 H 7 , C(O)CH 3 or C(O)OCH 3 ) with [P(C 6 H 5 ) 4 ][HFe 3 (CO) 11 ] have been studied. Depending on the reaction conditions the complexes [P(C 6 H 5 ) 4 ][Fe 3 (CO) 10 (μ 3 -CCH 2 R)] ( A ) and [P(C 6 H 5 ) 4 ][HFe 3 (CO) 9 (μ 3 -CCHR)] ( B ) can be isolated. The two types of complexes are interrelated by the addition of ( B → A ) or loss ( A → B ) of carbon monoxide. In two cases (R = C 6 H 5 , C 3 H 7 ) the transformation B → [P(C 6 H 5 ) 4 ][Fe 3 (CO) 9 (μ 3 -CCR)] has been observed in refluxing 2-methoxyethanol, and for these two alkynes all the transformations have been observed on a triiron unit.

Reactivity of phosphinoalkynes toward [HFe3(CO)9(CCH2)]−

Abstract The reactions of triphenylphosphine and (diphenylphosphino)alkynes Ph 2 PCCR (R = CH 3 , C 6 H 5 , C 6 H 4 CH 3 , C(CH 3 ) 3 ) or C(O)OCH 3 ) with [PPh 4 ][HFe 3 (CO) 9 (μ 3 -η 2 -CCH 2 )] have been studied. The complexes [PPh 4 ] [Fe 3 (CO) 9 (μ 3 -CCH 3 )L] (L,PPh 3 or Ph 2 PCCR) were isolated in high yields. The reaction involves migration of hydride which transforms the vinylidene ligand into an ethylidyne ligand. (Diphenylphosphino)alkynes are coordinated to metal atoms only through the phosphine centre and the alkyne group remains uncoordinated. The reaction of the new complexes with Co 2 (CO) 8 has been studied.