FAB Mass Spectra Research Articles

DNA interaction, antimicrobial, electrochemical and spectroscopic studies of metal(II) complexes with tridentate heterocyclic Schiff base derived from 2′-methylacetoacetanilide

A new Schiff base ligand (HL) was synthesized by the condensation reaction between 2′-methyleacetoacetanilide and 2-amino-3-hydroxypyridine. Its Co(II), Ni(II), Cu(II) and Zn(II) complexes were prepared by the interaction of the ligand with metal(II) chloride. They were characterized by elemental analysis, IR, 1H NMR, EPR, UV–Vis, magnetic susceptibility measurements, conductivity measurements and FAB-mass spectra. The interaction of the complexes with calf thymus DNA (CT-DNA) has been investigated by UV absorption, viscosity and cyclic voltammetry methods, and the mode of CT-DNA binding to the complexes has been explored. Furthermore, the DNA cleavage activity by the complexes was performed. It was found to be oxidative hydroxyl radical cleavage in the presence of 3-mercaptopropionic acid (MPA). The Schiff base and its complexes have been screened for their antibacterial ( Staphylococcus aureus, Escherichia coli, Bacillus subtilis and Pseudomonas aeruginosa) and antifungal ( Aspergillus niger, Rhizopus stolonifer, Rhizoctonia bataicola and Candida albicans) activities and the data reveal that the complexes have higher activity than the free ligand.

Synthesis, spectroscopic, electrochemical, DNA binding and photocleavage studies on coordination compounds of bis(4-aminophenyl)methane based novel Schiff bases

Two novel Schiff bases, 4,4′-methylenedianilidene-bis(3-methoxy-4-hydroxy-benzaldehyde) (L1) and 4,4′-methylenedianilidene-bis(3,4-dimethoxybenzaldehyde) (L2), have been prepared by condensing 4,4′-methylenedianiline (MDA) with vanillin and 3,4-dimethoxybenzaldehyde (DMB) respectively in ethanolic medium. Metal complexes of the above Schiff bases are prepared from salts of Cu(II), Zn(II), Co(II) and VO(IV). They are characterized by elemental analysis, molar conductivity, magnetic moment measurements, IR, 1H NMR, UV-Vis., FAB Mass, and EPR spectra. The elemental analysis data exhibit the formation of 1: 1 [M: L] ratio. The mode of bonding and the geometry of the complexes have been confirmed on the basis of IR, UV-Vis. and magnetic moment measurements. These data reveal a square-planar geometry for all the complexes except VO(IV) which has square-pyramidal geometry. The molar conductance measurements of the Schiff base complexes reveal the existence of non-electrolytic nature. The interactions of complexes with calf thymus DNA (CT-DNA) have been investigated by electronic absorption spectroscopy, viscosity measurements and cyclic voltammetry. The results indicate that the complex can bind to DNA by intercalation modes. The Schiff bases and their metal complexes have been evaluated for their antifungal and antibacterial activities against different species of pathogenic fungi and bacteria and their results are compared with standard drugs.

New homo- and hetero-bimetallic assemblies based on 2,5-bis(4-carboxyphenylamino)-3,6-dichloro-1,4-benzoquinone: synthesis, characterization, and magnetic properties

Synthesis, characterization, and magnetic properties of a new series of dinuclear compounds MIIM′IIL2(H2O)4 (where MII, M′II = Mn (1), Ni (2), Cu (3) and MII = Cu, M′II = Co (4), Ni (5); LH2 = 2,5-bis(4-carboxyphenylamino)-3,6-dichloro-1,4-benzoquinone) are reported. These complexes were characterized by elemental analyses, FAB mass spectra, thermogravimetric analysis, spectroscopic techniques (infrared, NMR, UV-Vis), and powder XRD studies. Magnetic properties investigated by SQUID magnetometer show antiferromagnetic coupling between the metal centers connected by the extensive π-delocalized ligand. Magnetic coupling constants (J) ranging from −1.01 to −3.01 cm−1 based on the Hamiltonian H = −2JS i S j have been obtained. The optimized geometry of the ligand derived from DFT is also reported.

Antibacterial, Spectral, and Thermal Aspects of Some [1,2,4-triazolo] [3,4-b][1,3,4]thiadiazine Based Heterochelates

New ligands 5-((4-(3-(pyridine-4-yl)-7H-[1,2,4]triazolo[3,4-b] [1, 3,4]thiadiazine-6-yl)phenylamino)methyl)quinolin-8-ol (L1) and 5-((3-(pyridine-4-yl)-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazine-6- ylamino)methyl)quinolin-8-ol (L2) have been synthesized. The obtained ligands were characterized by 1H NMR, 13C NMR, and IR spectroscopic techniques, and reacted with transition metal salts to afford metal containing heterochelates. The structures of the synthesized heterochelates were characterized using elemental analyses, infrared spectra, electronic spectra, magnetic measurements, FAB mass spectrum, and thermo gravimetric analyses. The kinetic parameters, such as order of reaction (n) and the energy of activation (Ea), are reported using the Freeman–Carroll method. Ligands and heterochelates were also screened for their in vitro antibacterial activity.

Application of Fast Atom Bombardment Collision-induced Dissociation Tandem Mass Spectrometry for Structural identification of Glycerolipids Isolated From Marine Sponge

Two types of glycerolipids [monoacylglycerols (MAG) and cyclitols] were isolated by reversed phase high-performanceliquid chromatography from the MeOH extracts of a marine sponge, and analyzed by fast atom bombardment mass spectrometry(FAB-MS) in positive-ion mode. FAB mass spectra of these compounds included protonated molecules [M+H]+ and abundantsodiated molecules [M+Na]+ from a mixture of m-NBA and NaI. The structures of these compounds were elucidated by FABcollisional-induced dissociation (CID)-tandem mass spectrometry. To find diagnostic ions for their characterization, these lipidswere analyzed by collision-induced dissociation (CID) B/E-linked scan. The CID B/E-linked scan of [M+H]+ and [M+Na]+ precursorions resulted in the formation of numerous characteristic product ions via a series of dissociative processes. The product ionsformed by charge-remote fragmentation (CRF) provided important information for the characterization of the acyl chain structuresubstituted at the glycerol backbone. Some of product ions were diagnostic for the presence of a glycerol backbone and acylchain structure, respectively.

Synthesis and characterization of some bis(cyclopentadienyl)titanium(IV) complexes with internally functionalized oximes(LH): sol–gel transformations of Cp2TiCl2, Cp2TiClL and Cp2TiL2 to nano‐sized anatase titania

AbstractSome bis(cyclopentadienyl)titanium(IV) complexes of the type [Cp2TiCl2−n{L}n] {where, n = 1 or 2; L = ONC(R)Ar; R = H or CH3 and Ar = C5H4N‐2, C4H3O‐2 or C4H3S‐2} have been synthesized by the metathetical reactions of Cp2TiCl2 with the sodium salt of internally functionalized oximes in 1:1 and 1:2 stoichiometry in anhydrous THF. All these red to brown colored solid derivatives have been characterized by elemental analyses, FT‐IR and NMR (1H and 13C{1H}) spectral studies. The FAB mass spectra of some representative derivatives indicate their monomeric nature. Oximato ligands in all the complexes appear to bind the titanium via N and O in a dihapto (${\bf \eta}^{2}$‐N, O) manner in the solid state. Thermogravimetric curves of [Cp2TiCl{ONC(CH3)C5H4N‐2}] and [Cp2Ti{ONC(CH3)C5H4N‐2}2] suggest the formation of hybrid materials CpTiO(Cl) and Cp2TiO, respectively, as the final products at 900 °C under nitrogen atmosphere. Sol–gel transformations of Cp2TiCl2, [Cp2TiCl{ONC(CH3)C5H4N‐2}] and [Cp2Ti{ONC(CH3)C5H4N‐2}2] yielded titania a–c, respectively, at low sintering temperature (600 °C). The powder XRD patterns, IR as well as Raman spectra of all these oxides indicate the formation of nano‐sized anatase phase. The SEM images of titania a–c indicate agglomers like surface morphologies. The absorption spectra of a–c exhibit an energy band gap in the range of 3.47–3.71 eV. Copyright © 2011 John Wiley & Sons, Ltd.

Chemically modified oximato complexes of titanium(IV) isopropoxide as new precursors for the sol–gel preparation of nano-sized titania: Crystal and molecular structure of [Ti{ONC10H16}4·2CH2Cl2

Abstract Reactions of [Ti(OPri)4] with various oximes, in anhydrous refluxing benzene yielded complexes of the type [Ti{OPri}4−n{L}n], where, n = 1–4 and LH = (CH3)2C NOH (1–4), C9H16C NOH (5–8) and C9H18C NOH (9–12). The compounds were characterized by elemental analyses, molecular weight measurements, FAB-mass, FT-IR and NMR (1H, 13C{1H}) spectral studies. The FAB-mass spectra of mono- (1), and di- (2), (6), (10) substituted products indicate their dimeric nature and that of tri- (3) and tetra- (4), (8) substituted derivatives suggest their monomeric nature. Crystal and molecular structure of [Ti{ONC10H16}4·2CH2Cl2] (8A) suggests that the oximato ligands bind the metal in a dihapto η2-(N, O) manner, leading to the formation of an eight coordinated species. Thermogravimetric curves of (3), (6) and (10) exhibit multi-step decomposition with the formation of TiO2 as the final product in each case, at 900 °C. Low temperature (∼600 °C) sol–gel transformations of (2), (3), (4), (6), (7) and (8) yielded nano-sized titania (a), (b), (c), (d), (e) and (f), respectively. Formation of anatase phase in all the titania samples was confirmed by powder XRD patterns, FT-IR and Raman spectroscopy. SEM images of (a), (b), (c), (d), (e) and (f) exhibit formation of nano-grains with agglomer like surface morphologies. Compositions of all the titania samples were investigated by EDX analyses. The absorption spectra of the two representative samples, (a) and (f) indicate an energy band gap of 3.17 eV and 3.75 eV, respectively.

Separation and identification of a new saponin from the flowers of Guaiacum officinale L.

A triterpenoid saponin, guaianin O (1), oleanolic acid 3-O-{α-L-rhamnopyranosyl-(1 → 2)-[β-D-glucopyranosyl-(1 → 3)]-α-L-arabinopyranoside}-28- O-[β-D-glucopyranosyl]-ester, was isolated from the n-butanol extract of flowers of Guaiacum officinale L. The structural elucidation of 1 was accomplished by extensive studies of both one and two dimensional 1H, 13C-NMR spectra, the FAB mass spectrum, and alkaline and acid hydrolyses.

Antibacterial, spectral and thermal aspects of some novel first transition metal‐based heterochelates

AbstractA new ligand, 5‐{[5‐(pyridine‐4‐yl)‐1,3,4‐oxadiazole‐2‐ylthio]methyl}quinoline‐8‐ol (K), was synthesized by base‐catalysed reaction of 5‐chloromethyl‐8‐hydroxy quinoline (CMQ) and 5‐(pyridine‐4‐yl)‐1,3,4‐oxadiazole‐2‐thiol. The obtained ligand K was characterized by 1H NMR, 13C NMR and IR spectroscopic techniques and reacted with transition metal salts to afford metal‐containing heterochelates. The structures of the synthesized heterochelates were characterized using elemental analyses, infrared spectra, electronic spectra, magnetic measurements, FAB mass spectrum and thermogravimetric analyses. The kinetic parameters such as order of reaction (n) and the energy of activation (Ea) are reported using the Freeman–Carroll method. The pre‐exponential factor (A), the activation entropy (ΔS#), the activation enthalpy (ΔH#) and the free energy of activation (ΔG#) were calculated. Heterochelates were also screened for their in vitro antibacterial activity against a range of Gram‐positive (Bacillus substilis, Staphylococcus aureus) and Gram‐negative (Escherichia coli, Serratiamarcescens) organisms. Copyright © 2010 John Wiley & Sons, Ltd.

Spectres De Masse FAB En Mode Positif De Composes Moleculaires Oxygenes Du Baryum

FAB mass spectra of condensation products of barium with oxygenated compounds allow to obtain analytical information about the structure of these compounds.

Novel Mn(III) heterochelates: synthesis, thermal, spectroscopic, and coordination aspects

This article describes the synthesis, structural features, and thermal studies of novel Mn(III) heteroche- lates of the type (Mn(SBn)(L)(H2O))� xH2 O( H 2SBn = Nicotinic acid (1-(3-methyl-5-oxo-1-phenyl-4,5 dihydro- 1H-pyrazol-4yl)-acylidene)-hydrazide where acyl = acetyl (H2SB1); benzoyl (H2SB2); propionyl (H2SB3); buteryl (H2SB4); phenyl acetyl (H2SB5); and HL = 5-Chloro-7- iodo-8-hydroxyquinoline (clioquinol)). The heterochelates have been characterized on the basis of elemental analyses, magnetic susceptibility measurements, cyclic voltammetric studies, (FTIR and electronic) spectra, and thermal studies. The FAB mass spectrum of (Mn(SB1)(L)H2O)� 3H2O has been carried out. The cyclic voltammetric studies reveal that quasi-reversible reduction process of Mn(III)/Mn(II) coupled system suggesting that the ligands readily desta- bilize higher oxidation states of metal ion. Kinetic parameters such as order of reaction (n) and the energy of activation (Ea) were calculated using Freeman-Carroll method. The pre-exponential factor (A), the activation entropy (S*), the activation enthalpy (H*), and the free energy of activation (G*) were calculated using Horowitz- Metzger equations.

Conventional and microwave assisted synthesis of Some new N-[(4-oxo-2-substituted aryl −1, 3-thiazolidine)-acetamidyl]-5-nitroindazoles and its antimicrobial activity

Several new N-[(4-oxo-2-substituted aryl-1, 3-thiazolidine)-acetamidyl]-5-nitroindazoles ( 4a– l) were synthesized from N-(arylidene amino acetamidyl)-5-nitroindazoles ( 3a– l). The reactions were carried out by both conventional as well as microwave method. The structures of these compounds were confirmed by IR, 1H NMR, 13C NMR, FAB-mass spectra and also by microanalytical data. The newly synthesized compounds were evaluated for their antimicrobial activity against variety of bacterial and fungal strains. The compounds 4g and 4h showed the maximum antibacterial activity (MIC 11 and 10 μg/mL) against Escherichia coli and antifungal activity (MIC 9 and 8 μg/mL) against Fusarium oxysporum.

Synthesis, physicochemical, antimicrobial, and 3D molecular modeling studies of oxomolybdenym(V) and dioxomolybdenum(VI) complexes with a Schiff base isonicotinoyl(5-bromo-2-hydroxybenzylidene)hydrazide

Synthesis of some new oxomolybdenum(V) and dioxomolybdenum(VI) complexes with a Schiff base isonicotinioyl(5-bromo-2-hydroxybenzylidene)hydrazide (L) derived from 5-bromosalicylaldehyde and isonicotinoylhydrazide are reported. The complexes have been characterized by elemental analyses, molar conductance, magnetic susceptibility data, IR, UV-Vis, EPR, 1H NMR, and FAB mass spectral studies. The physicochemical studies and spectral data indicate that L acts as a monovalent tridentate chelating agent. The FAB mass and X-band EPR spectra indicate that the pentavalent Mo in the complex is monomeric in nature. The X-ray diffraction studies of the complex [MoO(L)Cl2] (I) correspond to the orthorhombic crystal lattice with the unit cell dimensions a = 16.11, b = 12.20, and c = 7.5 A. The electrochemical behavior of the complex was investigated by cyclic voltammetry. All the complexes are found to be neutral with the distorted octahedral geometry. The thermal properties of the complex I were investigated by thermogravimetric techniques. The ligand L and the complexes I and [MoO2(L)Cl] (II) were screened for their in vitro antimicrobial activity. The complexes exhibited higher activity than L. The 3D molecular modeling and analysis for bond length and bond angles have also been carried out for complex I.

Synthesis, characterization, antimicrobial, and DNA cleavage studies of metal complexes of coumarin Schiff bases

Co(II), Ni(II), Cu(II), and Zn(II) complexes of the Schiff bases formed by the condensation of 8-formyl-7-hydroxy-4-methyl-coumarin with 3-amino-pyridine (L1) and 3-amino-2-chloro-pyridine (L2) are synthesized and characterized by various physico-chemical methods. The FAB-mass spectra of the ligand L1 and its Zn(II) complex are reported herewith. Thermal studies with Co(II) and Ni(II) complexes of both the ligands L1 and L2 are also reported. From the above studies, it is concluded that the ligand L1 acts as a bidentate ligand coordinating through azomethine nitrogen and phenolic oxygen of coumarin moiety via deprotonation, and ligand L2 acts as a tridentate ligand coordinating through azomethine nitrogen, phenolic oxygen of coumarin, and chlorine of pyridine moiety. All the complexes showed an octahedral geometry with a slight distortion in Cu(II) complexes. The fluorescence studies are carried out for ligand L1 with its Co(II), Ni(II), Cu(II), and Zn(II) complexes. The ligands and the complexes were screened for antibacterial and antifungal activities in vitro. The antitubercular activities are carried out by middle Brook method for all the compounds. The MIC values, cytotoxicity properties, and DNA cleavage studies are carried out for most active ligand L2, Co(II), and Cu(II) complexes.

Synthesis, spectral characterization, and antimicrobial studies of metal complexes of the Schiff base derived from [4-amino-N-guanylbenzene sulfonamide] and salicylaldehyde

Sulfaguanidinesalicylaldimine is a good bacteriostatic and a good complexing agent. Schiff-base complexes of Cu(II), Ni(II), Co(II), Zn(II), Cd(II), VO(IV), and UO2(VI) have been synthesized. The structural features of the complexes have been confirmed by microanalytical data, FAB mass, IR, UV-Vis, 1H-NMR, and EPR spectra. Molar conductance indicates the presence of nonelectrolytes. Spectroscopic and other analytical studies reveal the square-planar geometry for copper, square-pyramidal geometry for oxovanadium, seven-coordinate UO2(VI) complex, and octahedral geometry for other complexes. The EPR spectrum of the copper complex in the powdered form at 77 K was recorded. The redox behavior of the copper and oxovanadium complexes was studied using cyclic voltammetry. Antimicrobial activities of the compounds have been studied against microorganisms such as Escherichia coli, Staphylococcus aureus, and Candida by well-diffusion technique in DMSO. Some of the complexes have higher activity than the free ligand and the standard.

Synthesis, spectral, thermal, biological and 3D molecular modeling studies of oxidomolybdenum(v) and dioxidomolybdenum(VI) complexes derived from 2,4-dihydroxyacetophenone isonicotinoylhydrazone

Synthesis of some novel oxidomolybdenum(V) and dioxidomolybdenum(VI) complexes with a Schiff base, (2,4-dihydroxy acetophenoneisonicotinoylhydrazone) (DAIH), derived from 2,4-dihydroxy acetophenone and isonicotinoylhydrazide are reported. The complexes have been characterized by elemental analyses, molar conductance, magnetic susceptibility data, IR, UV-Vis, EPR, 1 H NMR and FAB mass spectral studies. The physico-chemical studies and spectral data indicate that the ligand (DAIH) acts as a monovalent tridentate chelating agent. The FAB mass and X-band EPR spectra indicate that the pentavalent Mo in the complex is monomeric in nature. The X-ray diffraction studies of the complex [MoO(DAIH)CL 2 ] correspond to orthorhombic crystal lattice with unit cell dimensions a = 16.64 A, b = 13.25 A and c = 9.56 A. All the complexes are found to be neutral with distorted octahedral geometry. The thermal behaviour of the complex [MoO(DAIH)Cl 2 ] was investigated by thermogravimetric techniques. The ligand (DAIH) and its two complexes [MoO(DAIH)COl 2 ], [MoO 2 (DAIH)Cl] were screened for their in vitro antibacterial activity. The complexes exhibited higher activity than the ligand (DAIH). The 3D molecular modeling and analysis for bond length and bond angles have also been carried out for one of the representative compounds, [MoO(DAIH)Cl 2 ].

Transition metal complexes of oximes derived from natural aldehydes : Synthesis, spectroscopic characterization and antimicrobial activities

A series of complexes of Co II , Zn II , Cd II and Hg II have been synthesized by the reactions of the metal chlorides with the sodium salt of oximes of citral (L 1 H) and citronellal (L 2 H) in 1: 2 stoichiometry in anhydrous dichloromethane. The oximes have been derived by the condensation reaction of hydroxylamine hydrochloride and citral or citronellal in 1: 1 molar ratio in ethanol. The plausible structure of these newly synthesized complexes has been proposed on the basis of elemental analysis, molar conductance and various, spectral (IR, UV-Vis, 1 H and 13 C{ 1 H} NMR) studies and four coordinated geometries have been assigned to these complexes. FAB mass spectra of 1 and 3 revealed the monomeric nature of these complexes. The powder XRD studies confirm the crystalline nature of the complexes. Studies were conducted to assess-the growth inhibiting potential of the complexes and oximes against three bacterial strains, S. aureus, B. subtilis Gram +ve and E. coli Gram -ve bacteria and two fungal strains, F. moniliformae and M. phaseolina. All complexes and oximes possess strong inhibitory action against microorganism. The results of antibacterial activity show that the Gram +ve bacteria S. aureus and B. subtilis are more susceptible than the Gram -ve bacteria E. coli. The antimicrobial activities of the complexes are found to be more than those of free oximes.

Synthesis, characterization, DNA binding, photo-induced DNA cleavage, and antimicrobial activity of metal complexes of a Schiff base derived from bis(3-aminophenyl)malonamide

The peptide linkage Schiff base (H2L) and its complexes have been synthesized and fully characterized by elemental analysis, UV–Vis, FTIR, 1H-NMR, 13C-NMR, EPR, and FAB-mass spectra. The stoichiometry of the complexes is [ML] (where M = Cu(II), Co(II), Ni(II), Zn(II), and VO(IV)). All the complexes exhibit square-planar geometry except the vanadyl complex which has square-pyramidal geometry. Interactions of the complexes and free ligand with double-stranded calf thymus DNA (CT-DNA) are studied by UV-spectrophotometric, electrochemical, and viscosity measurements. The data suggest that all the complexes form adducts with DNA and distort the double helix by changing the base stacking. Vanadyl complex forms a weaker adduct to CT-DNA than other complexes, probably due to the square-pyramidal geometry. CT-DNA induces extensive distortion in the planarity of vanadyl complex as EPR spectral calculations reveal. The intrinsic binding constants (K b) of [ZnL], [CuL], [CoL], and [NiL] are 1.1 × 105, 1.4 × 105, 0.8 × 105, and 0.6 × 105 M−1, respectively. Photo-induced DNA cleavage indicates that all complexes cleave DNA effectively. Control DNA cleavage experiments using pUC19 supercoiled (SC) DNA and minor groove binder distamycin suggest major groove binding for the synthesized complexes. The antimicrobial results indicate that the complexes inhibit the growth of bacteria and fungi more than the free ligand.

A Novel Biosynthetic Pathway of Archaetidyl-myo-inositol via Archaetidyl-myo-inositol Phosphate from CDP-archaeol and d-Glucose 6-Phosphate in Methanoarchaeon Methanothermobacter thermautotrophicus Cells

Ether-type inositol phospholipids are ubiquitously distributed in Archaea membranes. The present paper describes a novel biosynthetic pathway of the archaeal inositol phospholipid. To study the biosynthesis of archaetidylinositol in vitro, we prepared two possible substrates: CDP-archaeol, which was chemically synthesized, and myo-[(14)C]inositol 1-phosphate, which was enzymatically prepared from [(14)C]glucose 6-phosphate with the inositol 1-phosphate (IP) synthase of this organism. The complete structure of the IP synthase reaction product was determined to be 1l-myo-inositol 1-phosphate, based on gas liquid chromatography with a chiral column. When the two substrates were incubated with the Methanothermobacter thermautotrophicus membrane fraction, archaetidylinositol phosphate (AIP) was formed along with a small amount of archaetidylinositol (AI). The two products were identified by fast atom bombardment-mass spectrometry and chemical analyses. AI was formed from AIP by incubation with the membrane fraction, but AIP was not formed from AI. This finding indicates that archaeal AI was synthesized from CDP-archaeol and d-glucose 6-phosphate via myo-inositol 1-phosphate and AIP. Although the relevant enzymes were not isolated, three enzymes are implied: IP synthase, AIP synthase, and AIP phosphatase. AIP synthase was homologous to yeast phosphatidylinositol synthase, and we confirmed AIP synthase activity by cloning the encoding gene (MTH1691) and expressing it in Escherichia coli. AIP synthase is a newly found member of the enzyme superfamily CDP-alcohol phosphatidyltransferase, which includes a wide range of enzymes that attach polar head groups to ester- and ether-type phospholipids of bacterial and archaeal origin. This is the first report of the biosynthesis of ether-type inositol phospholipids in Archaea.

Diphosphine Compounds, Part III: UV/Visible Spectroscopy and Novel Routes to Functionalized Diphosphine-M(CO)6 Complexes (M = W, Mo, or Cr)

Reaction of coordinated (diphenylphosphino)methane and ketones or aldehydes have been characterized by 31P{H1}-NMR, 1H{31P}-NMR, and UV/vis spectroscopy in dichloromethane. Group VI metals hexacarbonyl [M(CO)6 where M = Cr, Mo, and W] reacted with (diphenylphosphino)methane, [(Ph2P)2CH2], to give [(OC)4M{(Ph2P)2CH2}] depending upon the reaction conditions. Condensation of [(CO)4M{(Ph2P)2CH2}] with different ketones or aldehydes forms [(CO)4M{(Ph2P)2C = CR1R2}]. Complexes of the types [(OC)4M{(Ph2P)2C = CR1R2}] reacted with hydrazine in a Michael addition to give [(CO)4M{(Ph2P)2CHC(R1R2)NHNH2}](1.3a–e), which condensed with different ketones and aldehydes to give complex of the type [(CO)4M{(Ph2P)2CHC(R1R2)NHN = C(R3)] (1.4a–e). The structures of the complexes are discussed on the basis of elemental analysis (EA), IR,1H-NMR, 31P-NMR spectroscopic data, and FAB mass spectra. The UV/vis spectra show two absorption bands with the low energy band moving to lower energy with increasing substitution on the (diphenylphosphino) methane (dppm) (a bathochromic effect).