Synthesis and photoelectron spectroscopic studies of N(CH2CH2NMe)3P=E (E = O, S, NH, CH2)

The synthesis and the crystal and molecular structure of N(CH(2)CH(2)NMe)(3)P=CH(2) is reported. The P-N(ax) distance is rather long in N(CH(2)CH(2)NMe)(3)P=CH(2). The ylide N(CH(2)CH(2)NMe)(3)P=CH(2) proved to be a stronger proton acceptor than proazaphosphatrane N(CH(2)CH(2)NMe)(3)P, since it was shown to deprotonate N(CH(2)CH(2)NMe)(3)PH(+). The extremely strong basicity of the ylide is in accordance with its low ionization energy (6.3 eV), which is the lowest in the presently investigated series N(CH(2)CH(2)NMe)(3)P=E (E: CH(2), NH, lone pair, O and S), and to the best of our knowledge it is the smallest value observed for a non-conjugated phosphorus ylide. Computations reveal the existence of two bond strech isomers, and the stabilization of the phosphorus centered cation by electron donation from the equatorial and the axial nitrogens. Similar stabilizing effects operate in the case of protonation of E. A fine balance of these different interactions determines the P-N(ax) distance, which is thus very sensitive to the level of the theory applied. According to the quantum mechanical calculations, methyl substitution at the equatorial nitrogens flattens the pyramidality of this atom, increasing its electron donor capability. As a consequence, the PN(ax) distance in the short-transannular bonded protonated systems and the radical cations is longer by about 0.5 A in the N(eq)(Me) than in the N(eq)(H) systems. Accordingly, isodesmic reaction energies show that a stabilization of about 25 and 10 kcal/mol is attributable to the formation of the transannular bond in case of N(eq)(H) and the experimentally realizable N(eq)(Me) species, respectively.     

Synthesis,characterization, biological applications,and molecular docking studies of amino-phenol-derived mixed-ligand complexes with Fe(III), Cr(III), and La(III) ions

A new series of Fe(III), Cr(III), and La(III) mixed-ligand complexes, resulting from the interaction of 2-aminophenol with 2-hydroxy acetophenone (HL₁) as primary ligand and L- histidine (L₂) as a secondary ligand, has been investigated using various physicochemical studies such as elemental analyses, molar conductivity, magnetic moment, infrared, UV/Vis, ¹H NMR, and mass spectroscopic techniques. The microanalytical results indicate that the mixed ligand complexes were designed in a 1:1:1 M ratio. The electronic spectral data indicated that all the synthesized complexes have an octahedral structure. The disc diffusion assay was used to determine the disc inhibition zone (IZ, mm) and minimum inhibitory concentration (MIC, g/mL) of the investigated compounds against the growth of the pathogenic bacterial strains S. aureus, E. faecalis, P. aeruginosa, Klebsiella sp., and E. coli. The MTT test was used to determine the cytotoxicity of these reported compounds against the human hepatocellular liver cancer (HEPG-2) cell lines. The molecular docking study for the compounds against the EGFR tyrosine kinase receptor (PDB code: 1 M17) was conducted to examine the interactions in protein–ligand complexes. Furthermore, the biological activity of the ligand was investigated using quantitative structure–activity relationship studies (QSAR).     

Synthesis, characterization, electro chemistry, catalytic and biological activities of ruthenium(III) complexes with bidentate N, O/S donor ligands

New hexa-coordinated ruthenium(III) complexes of the type [RuX(2)(EPh(3))(2)(L)] (E=P or As; X=Cl or Br; L=monobasic bidentate Schiff base derived from the condensation of benzhydrazide with furfuraldehyde, 2-acetylfuran and 2-acetylthiophene) have been synthesized from the equimolar amounts of [RuX(3)(EPh(3))(3)] or [RuBr(3)(PPh(3))(2)(MeOH)] and Schiff bases in benzene. The new complexes have been characterized by analytical, spectral (IR, electronic and EPR), magnetic moment, and cyclic voltammetry. An octahedral structure has been tentatively proposed. All the complexes have exhibited catalytic activity for the oxidation of benzyl alcohol, cyclohexanol and cinnamylalcohol in the presence of N-methylmorpholine-N-oxide as co-oxidant. All the new complexes were found to be active against the bacteria such as E. coli, Pseudomonas, Salmonella typhi and Staphylococcus aureus. The activity was compared with standard Streptomycin.     

Two new XP(O)[NHC(CH3)3]2 phosphoramidates,with X = (CH3)2N and [(CH3)3CNH]2P(O)(O)

In N,N′‐di‐tert‐butyl‐N′′,N′′‐dimethylphosphoric triamide, C₁₀H₂₆N₃OP, (I), and N,N′,N′′,N′′′‐tetra‐tert‐butoxybis(phosphonic diamide), C₁₆H₄₀N₄O₃P₂, (II), the extended structures are mediated by P(O)...(H—N)₂ interactions. The asymmetric unit of (I) consists of six independent molecules which aggregate through P(O)...(H—N)₂ hydrogen bonds, giving R₂¹(6) loops and forming two independent chains parallel to the a axis. Of the 12 independent tert‐butyl groups, five are disordered over two different positions with occupancies ranging from to . In the structure of (II), the asymmetric unit contains one molecule. P(O)...(H—N)₂ hydrogen bonds give S(6) and R₂²(8) rings, and the molecules form extended chains parallel to the c axis. The structures of (I) and (II), along with similar structures having (N)P(O)(NH)₂ and (NH)₂P(O)(O)P(O)(NH)₂ skeletons extracted from the Cambridge Structural Database, are used to compare hydrogen‐bond patterns in these families of phosphoramidates. The strengths of P(O)[...H—N]_x (x = 1, 2 or 3) hydrogen bonds are also analysed, using these compounds and previously reported structures with (N)₂P(O)(NH) and P(O)(NH)₃ fragments.     

Synthesis, characterization and reactivity of some novel dinuclear mixed-ligand peroxouranium(VI) complexes

Novel anionic dinuclear mixed-ligand peroxo complexes of the type [(UO₂)₂(O₂)₃L(H₂O)₂]³⁻ (L = Histidinate, aspartate, salicylate, Imidazolate and glutamate) have been synthesized from the interaction of uranyl ion (UO₂²⁺) with peroxide (O₂²⁻) in the presence of the respective coligand (L) at pH 9–10. The sparingly soluble complexes were characterized by elemental analyses, FT-IR, laser Raman (LR) and UV-vis spectroscopy and solution electrical conductance measurements. Based on these studies, a double bridged dinuclear structure involving one peroxo and the mixed ligand L (via-COO⁻) has been tentatively proposed. Infra-red coupled with LR spectra evidenced structurally different metal bound peroxides (ν² and σ:σ). An aqueous solution of the salicylate and aspartate complexes have been shown to convert triphenylphosphine (PPh₃), cyclohexene, styrene and SO₂ to the corresponding OPPh₃, 1,2 cyclohexanediol, phenylethyleneglycol and SO₄²⁻, respectively.     

Synthesis,characterization, and antimicrobial activities of Cu(I), Ag(I), Au(I), and Co(II) complexes with [CH3N(CH2PPh2)2]

Transition metal complexes of ditertiary aminomethylphosphine ligand, (Ph₂PCH₂)NCH₃ [N,N‐bis(diphenylphospinomethyl)aminomethane], dppam, with metal ions which are Ag(I), Au(I), Cu(I), and Co(II) have been synthesized under nitrogen atmosphere by the Schlenk method. [Ag(dppam)₂]NO₃ ( 1 ), [Au(dppam)₂]Cl ( 2 ), and [Cu(dppam)₂]Cl ( 3 ) complexes have been isolated as colorless solids, whereas [CoCl₂(dppam)] ( 4 ) complex as a blue solid. All complexes have been characterized by atomic absorption, FT‐IR, NMR (¹H, ¹³C, ³¹P) spectroscopic, thermogravimetric/differantial thermal analysis (TG/DTA), and elemental analysis techniques. Antimicrobial activity of 1 , 2 , 3 , and 4 were studied in vitro on 13 bacteria and 4 yeasts. The cobalt(II) phosphine complex has shown the best antimicrobial activity in comparison with the other metal complexes. © 2005 Wiley Periodicals, Inc. Heteroatom Chem 16:484–491, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20145     

Synthesis and Reaction Chemistry of Sb(ECH2CH2NMe2)3 (E = O,S)

The antimony aminoalkoxide and aminothiolates Sb(ECH₂CH₂NMe₂)₃ [E = O ( 1 ), S ( 2 )] were synthesized and their ability to form adducts with other metal moieties investigated. Compound 1 forms 1:1 adducts with NiI₂ ( 3 ) and M(acac)₂ [M = Cd ( 4 ), Ni ( 5 )], while 2 undergoes ligand exchange with AlMe₃ to afford Me₂AlSCH₂CH₂NMe₂ ( 6 ). The structures of 2 – 4 and 6 were determined. Compound 2 incorporates three S, N‐chelating ligands though the interaction with nitrogen is weaker than in analogous alkoxide complexes. Product 3 reveals one iodine has migrated from nickel to antimony, and all three alkoxide ligands bridge the two metals through μ₂‐O atoms. In contrast, in 4 , only one alkoxide links the antimony and cadmium. Compound 6 adopts the same structure, a chelating S,N ligand generating a tetrahedral center at aluminum, as known tBu₂AlSCH₂CH₂NR₂ species (R = Me, Et).     

Synthesis,characterization, and catalytic activity of half-sandwich ruthenium complexes with pyridine/phenylene bridged NHC = E (NHC = N-heterocyclic carbene,E = S,Se) ligands

Three half-sandwichruthenium(II) complexes with pyridine/phenylene bridged NHC = E (NHC = N-heterocyclic carbene, E = S, Se) ligands [Ru(p-cymene)L](PF₆)_1–2 ( 1a–1c , L = ligand) were synthesized and characterized. All ruthenium complexes were fully characterized by ¹H and ¹³C NMR spectra, mass spectrometry, and single-crystalX-ray diffraction methods. Moreover, the half-sandwich ruthenium complexes with NHC = E ligands showed highly catalytic activities towards to the tandem dehydrogenation of ammonia borane (AB) and hydrogenation of R–NO₂ to R–NH₂ at 353 K in water.     

Synthesis and structural characterization of new oxorhenium and oxotechnetium complexes with XN2S-tetradentate semi-rigid ligands (X = O, S, N)

Twelve novel oxo-technetium and oxo-rhenium complexes based on N2S2-, N2SO- or N3S-tetradentate semi-rigid ligands have been synthesised and studied herein. By reacting the ligands with a slight excess of suitable [MO]3+ precursor (ReOCl3(PPh3)2 or [NBu4][99gTcOCl4]), the monoanionic complexes of general formula [MO(Ph-XN2S)]- could be easily produced in high yield. The complexes have been characterized by means of IR, electrospray mass spectrometry, elemental analysis, NMR and conductimetry. The crystal structures of [PPh4][ReO(Ph-ON2S)] 1b and [NBu4][99gTcO(Ph-ON2S)] 1c have been established. The [MO]3+ moiety was coordinated via the two deprotonated amide nitrogens, the oxygen and the terminal sulfur atoms in 1b and 1c. In both compounds, the ON2S coordination set is in the equatorial plane, and the complexes adopted a distorted square-pyramidal geometry with an axial oxo-group. The chemical and structural identity of the different prototypic complexes (rhenium, 99gTc complexes and their corresponding 99mTc radiocomplexes) have been also established by a comparative HPLC study.     

Rhenium and technetium complexes with tridentate S,N,O ligands derived from benzoylhydrazine

A potentially tridentate ligand with an S,N,O donor set, H₂L, is formed by the reaction of N-[(diethylaminothiocarbonyl)benzimidoyl chloride with benzoylhydrazine. Reactions of H₂L with (NBu₄)[MOCl₄] complexes (M = Re, Tc) give five-coordinate, neutral oxo complexes of the composition [MOCl(L)].Mixed-ligand complexes of rhenium(V) containing the tridentate L^2? ligand and bidentate N,N-dialkyl-N′-benzoylthioureato ligands (R₂btu^?) are formed in high yields when (NBu₄)[ReOCl₄] is treated with mixtures of H₂L and HR₂btu. Another approach to the mixed-ligand products is the reaction of [ReOCl(L)] with an equivalent amount of HR₂btu.     

Synthesis and characterization of sulfuryl diazide, O2S(N3)2

Sulfuryl diazide, O(2)S(N(3))(2), previously described as an "exceedingly explosive" compound, has been isolated and characterized by IR (Ar matrix, gas) and Raman (solid) spectroscopy, and its structure has been determined by X-ray crystallography. It has a melting point of -15 °C and can be handled in small quantities in gas, liquid, and solid states. Vibrational spectroscopic studies suggest the presence of only one conformer in both gas and solid states, and the X-ray crystallography revealed an anti conformation of the two azido groups with respect to the NSN plane. Calculations predict the anti (C(2)) conformer to be 6.6 kJ mol(-1) lower in energy than the syn (C(s)) one at the CBS-QB3 level of theory. The related chlorosulfuryl azide, ClSO(2)N(3), has also been prepared and characterized by IR and Raman spectroscopy.     

Synthesis and spectroscopy of N3P3X5OCH=CH2 (X = Cl, F, OCH3, OCH2CF3, N(CH3)2) and N3P3X4(OCH=CH2)2 (X = Cl, N(CH3)2). Correlations of ultraviolet photoelectron spectroscopy and nuclear magnetic resonance data to electronic and geometrical structure

The syntheses of the vinyloxycyclotriphosphazene derivatives N3P3X5OCH=CH2 (X = OMe, OCH2CF3) and the N3P3(NMe2)4(OCH=CH2)2 isomeric mixture along with improved preparations of N3P3X5OCH=CH2 (X = F, NMe2) are reported. The interactions between the vinyloxy function and the cyclophosphazene in these and the previously reported N3P3Cl5 (OCH=CH2) and N3P3F6-n(OCH=CH2)n (n = 1-4) have been examined by ultraviolet photoelectron spectroscopy (UPS) and NMR spectroscopy. The UPS data for the chloro and fluoro derivatives show a strong electron-withdrawing effect of the phosphazene on the olefin that is mediated with decreasing halogen substitution. The 1H and 13C NMR data for N3P3X5OCH=CH2 (X = F, Cl, OMe, OCH2CF3, NMe2) show significant changes as a function of the phosphazene substituent. There is a linear correlation between the beta-carbon chemical shift on the vinyloxy unit and the phosphorus chemical shift at the vinyloxyphosphorus centers. The chemical shifts of the different phosphorus centers on each ring are also related in a linear fashion. These relationships may be understood in terms of the relative electron donor-acceptor abilities of the substituents on the phosphazene ring. The 1H NMR spectra of the N3P3(NMe2)4(OCH-CH2)2 isomeric mixture allow for assignment of the relative amounts of cis and trans isomers. A model for the observed cis preference in the formation of N3P3Cl4(OCH=CH)2 is presented.     

Synthesis,DNA-binding and photocleavage studies of cobalt(III) mixed-ligand complexes

Two novel complex ions [Co(bpy)₂IP]³⁺ and [Co(bpy)₂PIP]³⁺, have been prepared and characterized by EA, mass spectra, u.v.–vis., and cyclic voltammetry. The binding behavior of both complexes to calf thymus DNA (CT-DNA) has been investigated by spectroscopic methods, cyclic voltammetry, and viscosity measurements. The results suggest that both complexes bind to DNA by intercalation. Both promote cleavage of plasmid pBR 322 DNA from the supercoiled Form I to the open circular Form II upon irradiation. Mechanisms for photocleavage are proposed.     

Vanadium complexes of the N(CH2CH2S)3(3-) and O(CH2CH2S)2(2-) ligands with coligands relevant to nitrogen fixation processes

Vanadium(III) and vanadium(V) complexes derived from the tris(2-thiolatoethyl)amine ligand [(NS3)3-] and the bis(2-thiolatoethyl)ether ligand [(OS2)2-] have been synthesized with the aim of investigating the potential of these vanadium sites to bind dinitrogen and activate its reduction. Evidence is presented for the transient existence of (V(NS3)(N2)V(NS3), and a series of mononuclear complexes containing hydrazine, hydrazide, imide, ammine, organic cyanide, and isocyanide ligands has been prepared and the chemistry of these complexes investigated. [V(NS3)O] (1) reacts with an excess of N2H4 to give, probably via the intermediates (V(NS3)(NNH2) (2a) and (V(NS3)(N2)V(NS3) (3), the V(III) adduct [V(NS3)(N2H4)] (4). If 1 is treated with 0.5 mol of N2H4, 0.5 mol of N2 is evolved and green, insoluble [(V(NS3))n] (5) results. Compound 4 is converted by disproportionation to [V(NS3)(NH3)] (6), but 4 does not act as a catalyst for disproportionation of N2H4 nor does it act as a catalyst for its reduction by Zn/HOC6H3Pri2-2,6. Compound 1 reacts with NR1(2)NR2(2) (R1 = H or SiMe3; R2(2) = Me2, MePh, or HPh) to give the hydrazide complexes [V(NS3)(NNR2(2)] (R2(2) = Me2, 2b; R2(2) = MePh, 2c; R2(2) = HPh, 2d), which are not protonated by anhydrous HBr nor are they reduced by Zn/HOC6H3Pri2-2,6. Compound 2b can also be prepared by reaction of [V(NNMe2)(dipp)3] (dipp = OC6H3Pri2-2,6) with NS3H3. N2H4 is displaced quantitatively from 4 by anions to give the salts [NR3(4)][V(NS3)X] (X = Cl, R3 = Et, 7a; X = Cl, R3 = Ph, 7b; X = Br, R3 = Et, 7c; X = N3, R3 = Bu(n), 7d; X = N3, R3 = Et, 7e; X = CN, R3 = Et, 7f). Compound 6 loses NH3 thermally to give 5, which can also be prepared from [VCl3(THF)3] and NS3H3/LiBun. Displacement of NH3 from 6 by ligands L gives the adducts [V(NS3)(L)] (L = MeCN, nu CN 2264 cm-1, 8a; L = ButNC, nu NC 2173 cm-1, 8b; L = C6H11NC, nu NC 2173 cm-1, 8c). Reaction of 4 with N3SiMe3 gives [V(NS3)(NSiMe3)] (9), which is converted to [V(NS3)(NH)] (10) by hydrolysis and to [V(NS3)(NCPh3)] (11) by reaction with ClCPh3. Compound 10 is converted into 1 by [NMe4]OH and to [V(NS3)NLi(THF)2] (12) by LiNPri in THF. A further range of imido complexes [V(NS3)(NR4)] (R4 = C6H4Y-4 where Y = H (13a), OMe (13b), Me (13c), Cl (13d), Br (13e), NO2 (13f); R4 = C6H4Y-3, where Y = OMe (13g); Cl (13h); R4 = C6H3Y2-3,4, where Y = Me (13i); Cl (13j); R4 = C6H11 (13k)) has been prepared by reaction of 1 with R4NCO. The precursor complex [V(OS2)O(dipp)] (14) [OS2(2-) = O(CH2CH2S)2(2-)] has been prepared from [VO(OPri)3], Hdipp, and OS2H2. It reacts with NH2NMe2 to give [V(OS2)(NNMe2)(dipp)] (15) and with N3SiMe3 to give [V(OS2)(NSiMe3)(dipp)] (16). A second oxide precursor, formulated as [V(OS2)1.5O] (17), has also been obtained, and it reacts with SiMe3NHNMe2 to give [V(OS2)(NNMe2)(OSiMe3)] (18). The X-ray crystal structures of the complexes 2b, 2c, 4, 6, 7a, 8a, 9, 10, 13d, 14, 15, 16, and 18 have been determined, and the 51V NMR and other spectroscopic parameters of the complexes are discussed in terms of electronic effects.     

Adsorption Mechanism and Structure of the Montmorillonite Complexes with (CH(3))(2)XO (X=C, and S), (CH(3)O)(3)PO, and CH(3)-CN Molecules

The formation of complexes with different ligands in the interlayer space of montmorillonite saturated in Na(+), Mg(2+), Ca(2+), Co(2+), Cu(2+), Ni(2+), Fe(3+), and Cr(3+) was studied. Acetone, acetonitrile, dimethyl sulfoxide, and trimethylphosphate were used as ligands. The nature of the complexes was studied by means of X-ray diffraction, infrared spectroscopy, thermogravimetric analysis, microcalorimetry, and ab initio quantum mechanical methods. In all cases, the organic ligands penetrate into the interlayer space at room temperature, forming complexes stable in vacuum with the interlayer cations. The ligand-cation ratio depends on the valence of the saturating cation. The cation-ligand interaction in these complexes has an ion-dipole electrostatic nature. The complexes are formed by the direct interaction of the oxygen or nitrogen atom of ligand and the interlayer cation. Using the quantum mechanical approach, allow us to determine the disposition of the ligand in these complexes. In all cases, only one layer of ligands is present in the stable complexes. Copyright 2000 Academic Press.     

Synthesis and characterization of Pr(III), Nd(III) and Er(III) complexes with 2,6-pyridinedimethanol

The reactions of Ln(NO₃)₃?6H₂O (Ln=Pr, Nd or Er) with the potentially tridentate O,N,O chelating ligand 2,6-pyridinedimethanol (H₂pydm) in a 1:2 M ratio were investigated, and complexes with the formula [Ln(H₂pydm)₂(NO₃)₂](NO₃) (Ln=Pr or Nd) (1 and 2) and [Er(H₂pydm)₃](NO₃)₃ (3) were isolated. The compounds contain 10-coordinate Pr(III) and Nd(III) ions that crystallize in the triclinic space group P-1 while the 9-coordinate Er(III) complex crystallizes in the monoclinic system (P2₁/n). A new lanthanide complex, [Pr(H₂pydm)₃](Cl)₃?DMF (4), has been synthesized by reaction of PrCl₃?6H₂O and H₂pydm. The nine-coordinate Pr(III) is bound to three H₂pydm ligands. X-ray crystal structures of 1–4 reveal that the ligand coordinates tridentate via the pyridyl nitrogen and the two hydroxyl oxygens. The electronic absorption spectra of 1–4 show 4f–4f transitions.     

N/P-ethoxyphenyl/dithiocarbamato complexes of Au(III), As(III), Fe(III), Co(III) and Mo(V)

The complexes of Au(III), As(III), Fe(III), Co (III) and Mo(V) with N(p-ethoxyphenyl)-dithiocarbamate have been synthesized and characterized on the basis of elemental analyses, conductance measurements, infrared and electronic spectra, molecular weight determinations and magnetic moment data. The thermal behaviours of these complexes have been studied with the aid of TG and DTA techniques.     

Synthesis, structure, and physical properties for a series of trigonal bipyramidal M(II)-Cl complexes with intramolecular hydrogen bonds

A series of transition metal chloro complexes with the tetradentate tripodal tris(2-amino-oxazoline)amine ligand (TAO) have been synthesized and characterized. X-Ray structural analyses of these compounds demonstrate the formation of the mononuclear complexes [M(II)(TAO)(Cl)](+), where M(II) = Cr, Mn, Fe, Co, Ni, Cu and Zn. These complexes exhibit distorted trigonal-bipyramidal geometry, coordinating the metal through an apical tertiary amine, three equatorial imino nitrogen atoms, and an axial chloride anion. All the complexes possess an intramolecular hydrogen-bonding (H-bonding) network within the cavity occupied by the metal-bound chloride ion. The metal-chloride bond distances are atypically long, which is attributed to the effects of the H-bonding network. Nuclear magnetic resonance (NMR) spectroscopy of the Zn complex suggests that the solid-state structures are representative of that observed in solution, and that the H-bonding interactions persist as well. Additionally, density functional theory (DFT) calculations were carried out to probe the electronic structures of the complexes.     

Synthesis and characterization of rhenium(V) oxo complexes with N-[N-(3-diphenylphosphinopropionyl)glycyl]cysteine methyl ester. X-ray crystal structure of (ReO[Ph(2)P(CH(2))(2)C(O)-Gly-Cys-OMe(P,N,N,S)])

The PN(2)S chelate N-[N-(3-diphenylphosphinopropionyl)glycyl]-S-tritylcysteine methyl ester [PN(2)S(Trt)-OMe] was synthesized and reacted with ReOCl(3)(PPh(3))(2) and Ph(4)P[ReOCl(4)]. The reactions of both tritylated and detritylated ligands with Re(V)O precursors gave two diastereomers, 9a and 9b, of the ReO(PN(2)S-OMe) complex. The two isomers, produced in a 1:1 molar ratio, are stable and do not interconvert. They were separated by reverse-phase HPLC and characterized by NMR, FT-IR, and UV-visible spectroscopy and electrospray mass spectrometry. X-ray analysis established for 9a the presence in the solid of the syn isomer. Compound 9a, C(21)H(23)N(2)O(5)PSRe, crystallized from warm acetonitrile in the triclinic space group Ponemacr;, a = 9.828(2) A, b = 11.163(2) A, c = 11.641(2) A, alpha = 106.48(3) degrees, beta = 109.06(3) degrees, gamma = 102.81(3) degrees, V = 1085.7(4) A(3), Z = 2. The PN(2)S coordination set is in the equatorial plane, and the complex shows a distorted square pyramidal coordination. The anti configuration assigned to 9b is consistent with all the available physicochemical data. Follow-up of the reaction of the detritylated ligand with Ph(4)P[ReOCl(4)] in ethanol or acetonitrile indicated that the phosphorus atom of the chelate binds first to the metal and that this bond acts as the driving force for coordination.