scholarly journals Synthesis, Characterisation and Hydrolytic Reactions of the First Pentaisopropoxostannate Derivatives of Magnesium, Zinc and Cadmium

2007 ◽  
Vol 2007 (8) ◽  
pp. 458-460
Author(s):  
Jayshree Shahanl ◽  
Anirudh Singh
Keyword(s):  
Molecular Weight ◽  
Nmr Studies ◽  
Molar Ratios ◽  
Derivatives Of ◽  
C Nmr

Pentaisopropoxostannate derivatives of the types [{M[Sn(OPri)5](μ–Cl)}2] and [M{Sn(OPri)5}2] have been prepared by the reactions of MCl2 (M = Mg, Zn, and Cd) with NaSn(OPri)5 in 1:1 and 1:2 molar ratios, respectively, in benzene. All these derivatives have been characterised by elemental and isopropoxo group analyses, spectroscopic (IR, 1H and 13C NMR) studies, and molecular weight determinations. Two typical hydrolytic reactions of [Zn{Sn(OPri)5}2] have also been investigated.

scholarly journals Monoorganosilicon(IV) Complexes of 2-Aminocyclopentene-1-carbodithioic Acid and its N-/S-Alkyl Derivatives: Synthesis and Characterization

2021 ◽  
Vol 33 (12) ◽  
pp. 3134-3138
Author(s):  
Rajnish K. Sharma ◽  
Malti Sharma ◽  
Yashpal Singh
Keyword(s):  
Molecular Weight ◽  
Nitrogen Atom ◽  
13C Nmr ◽  
Synthesis And Characterization ◽  
Sulphur Atom ◽  
Nmr Studies ◽  
1H And 13C Nmr ◽  
Molar Ratios ◽  
Alkyl Derivatives ◽  
Derivatives Of

2-Aminocyclopentene-1-carbodithioic acid (ACDA) and its N-/S-alkyl derivatives of methylsilicon(IV) chloride have been synthesized by the reactions of MeSiCl3 with sodium salt of ACDA and its N-/S-alkyl derivatives in 1:1 and 1:2 molar ratios. All these complexes have been characterized by elemental analysis, molecular weight measurements and spectroscopic (IR, 1H and 13C NMR) studies. The central silicon atom is coordinated to two sulphur atoms or one sulphur atom and one nitrogen atom of the ligand moiety in all of these derivatives, resulting in five and six coordination.

Polymerization of n-butyl methylacrylate using bis(β- ketoamino)nickel(II)/MAO catalytic systems

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaohui He ◽  
Yiwang Chen ◽  
Yongming Liu ◽  
Muqing Chen ◽  
Shuxian Yu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Monomer Concentration ◽  
Polymerization Temperature ◽  
Moderate Activity ◽  
Polymerization Time ◽  
Catalytic Systems ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Broad Molecular Weight Distribution ◽  
C Nmr

AbstractThe polymerizations of n-butyl methylacrylate (nBMA) were carried out using bis(β-ketoamino)nickel(II) complexes (Ni[CH3C(O)CHC(NR)CH3]2: R = phenyl, 1; R = naphthyl, 2) in combination with methylaluminoxane (MAO) in toluene. The effect of parameters such as polymerization temperature, Al/Ni molar ratios, polymerization time, and monomer concentration, on catalytic polymerization activity and polymer molecular weights, were examined in detail. Both of the nickel(II) catalytic systems exhibited moderate activity, and produced P(nBMA) with high molecular weight and relatively broad molecular weight distribution (Mw/Mn=2.0~3.0. The obtained polymer has been characterized by means of FTIR, 1H NMR, 13C NMR, DSC, and WAXD technique and was confirmed to be syndio-rich stereospecific P(nBMA).

Preparation and Spectroscopic Characterisation of a Series of Heterobimetallic N-phenyldiethanolaminate-alkoxide Derivatives of Oxovanadium(V)

2005 ◽  
Vol 2005 (6) ◽  
pp. 352-355 ◽  
Author(s):  
Rajendra Singh Ghadwal ◽  
Ram C. Mehrotra ◽  
Anirudh Singh
Keyword(s):  
Molecular Weight ◽  
Spectral Studies ◽  
Metal Alkoxides ◽  
Nmr Studies ◽  
Mass Spectral ◽  
Elemental Analyses ◽  
Derivatives Of ◽  
Spectroscopic Characterisation

Reaction of VO(OPri)3 with two equivalents of N-phenyldiethanolamine (PhDEAH2) yields a homometallic complex [VO(PhDEA)(PhDEAH)] 1, which reacts with a number of metal alkoxides to afford heterobimetallic oxovanadium(V) complexes of the types [VO(PhDEA)2{M(OR)n-1}] [where PhDEA = C6H5N(CH2CH2O–)2], [M =: Al (n = 3, R = Pri) 2; Al (n = 3, R = But) 3; Ti (n = 4, R = Pri) 4; Zr (n = 4, R = Pri) 5; Nb (n = 5, R = Pri) 6; Ta (n = 5, R = Pri) 7. The derivative [VO(PhDEA)(OSiPh3)] 8 has been prepared by the equimolar interaction of [VO(PhDEA)(OPri)] with Ph3SiOH. All of these complexes have been characterised by spectroscopic (IR; 1H, 13C, 27Al and 51V NMR) studies, elemental analyses, and molecular weight measurements. The derivative 2 has also been characterised by FAB mass spectral studies, which supports for its monomeric nature.

Titanium(IV) Complexes of Monofunctional Bidentate Schiff Bases

1970 ◽  
Vol 25 (10) ◽  
pp. 1090-1094 ◽  
Author(s):  
S. R. Gupta ◽  
J. P. Tandon
Keyword(s):  
Molecular Weight ◽  
Schiff Base ◽  
Schiff Bases ◽  
General Type ◽  
Titanium Isopropoxide ◽  
Central Metal Atom ◽  
Central Metal ◽  
Coordination Numbers ◽  
Molar Ratios ◽  
Derivatives Of

Titanium (IV) complexes of monofunctional bidentate Schiff bases, such as salicylideneaniline, β-hydroxynaphthylideneaniline, benzylidene-o-aminophenol, benzylidene-2-hydroxyethylamine and benzylidene-2-hydroxy-n-propylamine have been prepared. The reactions between titanium isopropoxide and the Schiff bases in varying molar ratios resulted in the synthesis of several new derivatives of the general type, Ti (OPri)4-x (SB)x (where x = 1. 2. 3 or 4 and SB⊖ is the anion of the Schiff base SBH) in quantitative yields. The molecular weight determinations of some of the soluble derivatives indicate the possibility of coordination numbers five or seven for the central metal atom.

Tricarbonylferrole iron tricarbonyl derivatives: formation from thiophenes and iron atoms in a CO atmosphere and fluxional behaviour

1977 ◽  
Vol 55 (20) ◽  
pp. 3509-3514 ◽  
Author(s):  
Tristram Chivers ◽  
Peter L. Timms
Keyword(s):  
Nmr Studies ◽  
Warm Up ◽  
Metal Atoms ◽  
Iron Tricarbonyl ◽  
Derivatives Of ◽  
C Nmr

Co-condensation of metal atoms (Cr, Fe) with thiophenes [Formula: see text] (R = R′ = H, Me; R = H, R' = Me) at −196 °C leads to desulphurization of the thiophene. Warm-up of the iron–thiophene co-condensate in a CO atmosphere produces derivatives of tricarbonylferrole iron tricarbonyl, C4H2RR′Fe2(CO)6. 13C nmr studies of these complexes show that the tricarbonyl ferrole unit is static from −95 °C to +60 °C, while the π-Fe(CO)3 group exhibits fluxional behaviour. Addition of dienes or Me3P in hexane to the iron–thiophene co-condensate at −196 °C yields thermally unstable red solutions on melting.

Seven-coordinate metal carbonyl derivatives of cis-(CH3)2AsC(CF3)=C(CF3)As(CH3)2

1976 ◽  
Vol 54 (16) ◽  
pp. 2548-2556 ◽  
Author(s):  
William R. Cullen ◽  
Lynn M. Mihichuk
Keyword(s):  
Metal Carbonyl ◽  
Activation Parameters ◽  
Nmr Studies ◽  
H Nmr ◽  
Carbonyl Derivatives ◽  
Derivatives Of ◽  
C Nmr

The seven-coordinate complexes (L—L)M(CO)3X2 (M = Mo, W; X = Br, I; (L—L) = cis-(CH3)2AsC(CF3)=C(CF3)As(CH3)2) were prepared and characterized. 1H and 13C nmr studies at 25 and −70 °C suggest that the complexes are nonrigid. Similarly 1H nmr studies indicate the seven-coordinate (L—L)LMo(CO)2Br2 complexes are also nonrigid. The (L—L)L2Mo(CO)Br2 complexes (L is a monodentate phosphite or phosphine) are rigid at 25 °C and nonrigid at higher temperatures. Activation parameters are calculated for the motion of two of the complexes and possible mechanisms are discussed.

scholarly journals Di-n-butyltin(IV) Complexes Derived from Heterocyclic β-diketones and N-Phthaloyl Amino Acids: Preparation, Biological Evaluation, Structural Elucidation Based upon Spectral [IR, NMR (1H,13C,19F and119Sn)] Studies

2005 ◽  
Vol 3 (3-4) ◽  
pp. 201-215 ◽  
Author(s):  
Anurag Joshi ◽  
Shashi Verma ◽  
R. B. Gaurb ◽  
R. R. Sharma
Keyword(s):  
Amino Acids ◽  
Antimicrobial Activities ◽  
Biological Evaluation ◽  
Structural Elucidation ◽  
Nmr Studies ◽  
Molar Ratios ◽  
C Nmr

Stable, six coordinated Bu2SnLA type complexes have been prepared [where LH =RCOC:C(OH)N(C6H5)N:︹CCH3; R = -4-F-C6H4-(L1H), R = -4-Cl-C6H4-(L2H), R= -4-Br-C6H4-(L3H), R= -CF3(L4H) andAH=C(O)C6H4C(O)︹NCHR′COOH; R'= -H(A1H), -CH3(A2H), -CH(CH3)2(A3H)] by the interaction of 1:1:1 molar ratios of di-n-butyltin(IV) dichloride with corresponding organic moieties in refluxing benzene using two moles of Et3N as a base. In these complexes LH and AH behave as bidentate and coordination is taking place through oxygen, this is inferred from IR and13C NMR studies. These complexes possess tin atoms in skew trapezoidal bipyramidal geometry with the C-Sn-C angles ranging from 149.88°to 156.84°. Some of these complexes with their corresponding organic moieties (LH, AH) were tested for their antimicrobial activities.

In Search of New Approaches to Asymmetric Conjugate Addition: Screening Studies on the Use of [Zn(bpy*)X(R)] Reagents and α,β-Unsaturated Amide Michael Acceptors

2007 ◽  
Vol 72 (8) ◽  
pp. 1107-1121 ◽  
Author(s):  
Alexander J. Blake ◽  
Daniela Giunta ◽  
Jonathan Shannon ◽  
Maurizio Solinas ◽  
Francesca Walzer ◽  
...  
Keyword(s):  
Ligand Exchange ◽  
Conjugate Addition ◽  
Nmr Studies ◽  
Conjugate Additions ◽  
New Approaches ◽  
Michael Acceptors ◽  
Derivatives Of ◽  
Moderate Yield ◽  
C Nmr

Conjugate additions of [Zn(bpy*)Cl(Et)] (bpy* = 4,4'-di-tert-butyl-2,2'-bipyridine) to cyclohex-2-en-1-one are promoted by ZnMe2 in 88% ee but in moderate yield under CuI phosphoramidite catalysis. In the absence of ZnMe2 the [Zn(bpy*)Cl(Et)] is inactive indicating a Schlenk-type equilibrium. Other derivatives of [Zn(bpy*)Cl(R)] (R = Bu, 4-methylbenzyl), prepared in situ from [ZnCl(R)] and the bipyridine give low yields due to competing chloride abstraction. 13C NMR studies indicate facile organo-ligand exchange between [Zn(bpy*)(Et)2] and [Zn(bpy*)Cl2] complexes. In the presence of the bipyridine, [ZnBr(allyl)] disproportionates into [Zn(bpy*)Br2] and [Zn(bpy*)(allyl)2] species. In separate studies, simple (E)-MeCH=CHCONMeR (R = Me, OMe) α,β-unsaturated amides undergo asymmetric 1,4-addition of EtMgBr in 75-99% yield and 48-79% ee in the presence of the diphosphines JosiPhos or MeDuPhos and copper(I) sources.

Preparation, characterization, and antioxidant properties of polystyrenes with 4-methoxyphenol end groups

1983 ◽  
Vol 61 (1) ◽  
pp. 124-127 ◽  
Author(s):  
Brian K. Hunter ◽  
Kenneth E. Russell ◽  
Ataa K. Zaghloul
Keyword(s):  
Molecular Weight ◽  
Nuclear Overhauser Effect ◽  
Average Molecular Weight ◽  
Antioxidant Properties ◽  
Low Molecular Weight ◽  
Nmr Studies ◽  
Overhauser Effect ◽  
End Groups ◽  
Nuclear Overhauser ◽  
C Nmr

Polystyrenes with 4-methoxyphenol end groups have been prepared by the cationic polymerization of styrene in the presence of the phenol. The products range from 1:1 adduct to polymer of number-average molecular weight close to 3000. The 1:1 adduct separated from the reaction mixture was shown by nuclear Overhauser effect studies to be 2-(1-methylbenzyl)-4-methoxyphenol. Only about half of the polymer molecules have 4-methoxyphenol end groups. 13C nmr studies indicate that the polystyrene chains are attached principally at the 2-position of the phenol. The activity of the polymer as an antioxidant is comparable to that of corresponding low molecular weight methoxyphenols including butylated hydroxyanisole.

Phenolic Resins (II) – Influence of the Chemical Structure of High Molecular Weight Molecules on the Mechanisms of Cross-linking and on the Final Structure of the Resins

2003 ◽  
Vol 11 (4) ◽  
pp. 233-262 ◽  
Author(s):  
J. Bouajila ◽  
G. Raffin ◽  
H. Waton ◽  
C. Sanglar ◽  
J.O. Païsse ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chemical Structure ◽  
Physicochemical Characterization ◽  
Cross Linking ◽  
Phenolic Resins ◽  
Molar Ratios ◽  
Synthesis Parameters ◽  
Fragmentation Mechanisms ◽  
C Nmr

The physicochemical characterization of the structures of the oligomers (n < 4) in resols has been carried out by fragmenting monomers in LC/UV/MS and LC/UV/MS/MS. Fragmentation mechanisms are related to the numbers and positions of substituents on the aromatic ring and to the types of oligomer junctions. It was more difficult to determine the structures of phenol hemiacetals and dimer hemiacetals because of the large number of position isomers. The resols were prepared with differing molar ratios R = Formaldehyde/Phenol and catalysts. They were cross-linked using two industrially recommended heat cycles. The progression of resin cross-linking was determined by solid state 13C NMR (CP/MAS). The residual percentage of monomers and oligomers at n < 4 was determined in leachates (water and methanol) and characterized by LC/UV/MS. The results for cross-linking advancement were correlated with the various synthesis parameters (ratio R, type of catalyst and heat cycle).

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