B. Khera

Bis(indenyl)titanium(IV) and zirconium(IV) complexes of monofunctional bidentate salicylidimines

Abstract Dichlorobis(indenyl)-titanium(IV) and -zirconium(IV), (C9H7)2TiCl2 and (C9H7)2ZrCl2, react with bidentate Schiff bases such as salicylidene aniline, salicylidene-o-toluidine, salicylidene-m-toluidine and salicylidene-p-toluidine in a 1:1 molar ratio in refluxing tetrahydrofuran in the presence of triethylamine to yield complexes of the type (C9H7)2Ti(SB)Cl and (C9H7)2Zr(SB)Cl, respectively where SB is the anion of the corresponding Schiff base, SBH. The new derivatives have been characterised on the basis of their elemental analyses, conductance measurements and spectral (IR, 1H NMR and electronic) studies.

Reactions of Dichlorobis (Cyclopentadienyl) Titanium (IV) with Bident Ate Schiff Bases Derived from Salicylaldehyde and 4-Substituted Anilines

Abstract Dichlorobis (cyclopentadienyl) titanium(IV), Cp2TiCl2, reacts with bidentate Schiff bases such as salicylidene-4-anisidine, salicylidene-4-phenetidine, salicylidene-4-bromoaniline, salicylidene-4-iodoaniline and salicylidene-4-nitroaniline in a 1:1 molar ratio in refluxing tetrahydrofuran in the presence of trimethylamine, to yield Cp2Ti (SB)Cl, where (SB)− is the anion of the corresponding Schiff base, SBH. The derivatives have been characterised on the basis of their elemental analyses, molecular weights, conductance and spectral (IR, 1H NMR and electronic) characteristics.

Phthiocol Chelates of Bis(Cyclopentadienyl)titanium(IV)

Abstract A convenient method for the preparation of [Cp2TiL]+ X-complexes, where L is the conjugate base of 3-hydroxy-2-methyl-1,4-naphthaquinone or phthiocol, X− [dbnd] Br−, I−, ZnCl3(H2O)−, ROCS− 2 or R2NCS− 2 (R [dbnd] Me, Et or i-Pr) have been described. The complexes have been characterized on the basis of chemical analyses, electrical conductance and infrared spectral studies. These studies indicate that the complexes are 1:1 electrolytes in which the ligand L is chelating through the hydroxy and carbonyl oxygens of the phthiocol group.

Isolation of dithiocarbamate anions as salts of biscyclopentadienyl titanium(IV) chelates

Abstract A series of [Cp 2 TiL] + [RR′NCS 2 ] − complexes, where L is the conjugate base of acetylacetone, benzoylacetone or 8-hydroxyquinoline and R = CH 3 , R′ = C 6 H 5 CH 2 ; R = C 2 H 5 , R′ = C 6 H 4 CH 3 ; R = H, R′ = C 5 H 9 ; RR′ = C 6 H 12 , have been synthesised in aqueous medium by the reaction of [Cp 2 TiL] + Cl − with RR′NCS − 2 Na + . Conductivity measurements in nitrobenzene solution indicate that these complexes are electrolytes. Both the IR and NMR studies demonstrate that the ligand L is chelating in all these complexes. Consequently, tetrahedral coordination about the titanium atom is proposed. In addition to these studies, elemental analyses and magnetic susceptibility have been carried out for these complexes.

Bis (indenyl) Titanium(IV) Complexes of Monofunctional Bidentate Salicylidimines

A series of (C9H7)2Zr(SB)Cl complexes whereSB− is the anion of bidentateSchiff base derived from salicylaldehyde and 4-substituted anilines, viz. salicylidene-4-ansidine, salicylidene-4-phenetidine, salicylidene-4-chloroaniline, salicylidene-4-bromoaniline, salicylidene-4-iodoaniline and salicylidene-4-nitroaniline, have been synthesized by the reaction of bis(indenyl)zirconium(IV) dichloride andSchiff base (SBH) in 1:1 molar ratio in refluxingTHF in the presence of triethylamine. The new derivatives have been characterized on the basis of their elemental analyses, conductance measurements and spectral (IR,1H-NMR, UV-VIS) studies.

Isolation of Dithiocarbamate Anions as Salts of Bis(cyclopentadienyl)-zirconium(IV) Chelates

Abstract A series of [cp2ZrL]+[RR′NCS2]− complexes (where Lis the conjugate base of acetylacetone, benzoylacetone or 8-hydroxyquinoline (oxine) and R = CH3, R′ = C6H5CH2; R = C2H5, R′ = C6H4°CH3; R = H, R′ = C5H9; RR′ = C6H12) have been synthesised in aqueous medium by the reaction of [Cp2ZrL]+Cl− with RR′NCS2 −Na+. Conductivity measurements indicate that these complexes are 1:1 electrolytes in nitrobenzene. IR and 1H NMR spectral studies demonstrate that the ligand L is chelating in all these complexes. Consequently, tetrahedral coordination about the zireonium atom is proposed. In addition to these studies, elemental analyses and magnetic susceptibility have also been carried out for these complexes.

Salicylaldehydo chelates of bis(cyclopentadienyl) zirconium(IV)

A new series of organometallic ionic chelates of the type [Cp2Zr(sal)]+ [ROCS2/R′R″NCS2]−, where Hsal = salicylaldehyde;R =Me, Et, i-Pr ori-Bu andR′ =R″ =Me, Et, i-Pr;R′ =Me,R″ = benzyl orR′ =Et,R″ =m-tolyl, have been synthesized in aqueous medium by the reaction of [Cp2Zr(sal)]+Cl− andROCS2−K+/R′R″NCS2−Na+. These compounds have been characterized by chemical analyses, electrical conductance, electronic, IR and1H-NMR spectral studies. These studies indicate that the complexes are 1:1 electrolytes and the salicylaldehyde ligand is chelating in all these complexes. Therefore, a tetrahedral coordination about the zirconium atom is proposed.ZusammenfassungEine neue Gruppe von organometallischen ionischen Chelaten vom Typ [Cp2Zr(sal)]+ [ROCS2/R′R″NCS2]− (mit Hsal = Salicyladehyd;R =Me, Et, i-Pr oderi-Bu undR′ =R″ =Me, Et, i-Pr;R′ =Me,R″ = Benzyl oderR′ =Et,R″ =m-Tolyl) wurde in wäßrigem Medium mittels der Reaktion von [Cp2Zr(sal)]+Cl− mitROCS2−K+/R′R″NCS2−Na+ hergestellt. Die erhaltenen Verbindungen wurden mittels chemischer Analyse, elektrischer Leitfähigkeit und der IR- sowie1H-NMR-Spektren charakterisiert. Diese Untersuchungen zeigen, daß die Komplexe 1:1-Elektrolyte sind, wobei der Salicylaldehyd-Ligand in allen Fällen an der Chelatbildung beteiligt ist. Es wird daher für das Zirkoniumatom eine tetrahedrale Koordination vorgeschlagen.

Mono- and bisphenoxy derivatives of bis(indenyl)zirconium(IV)

Abstract A series of (C 9 H 7 ) 2 Zr(OAr)Cl and (C 9 H 7 ) 2 Zr(OAr) 2 complexes, where Ar = C 6 H 5 , p -ClC 6 H 4 , α-C 10 H 7 , or β-C 10 H 7 , have been synthesised by the reaction of bis(indenyl)zirconium(IV)-dichloride with an appropriate phenol in a 1:1 and 1:2 molar ratio in refluxing benzene in the presence of triethylamine. These complexes have been characterised by elemental analyses, conductance measurements and spectral (IR, 1 H NMR and electronic) studies.

Acetylacetonato bis(Indenyl)zirconium(IV) Dithiocarbamates

Abstract A series of [(C9H7)2ZrL]+[RR′NCS2]− complexes (where L is the conjugate base of acetylacetone and R = R′ = C2H5 or i-C3H7; R = CH3, R′ = C6H5CH2; R = C2H5, R′ = C6H4.CH3; R = C2H5, R′ = C6H11; RR′ = C6H12) have been synthesised in aqueous solution by the reaction of [(C9H7)2ZrL]+Cl− with RR′NCS2 −Na+. Conductivity measurements indicate that these complexes are 1:1 electrolytes in nitrobenzene. IR and 1H NMR spectral studies demonstrate that the acetylacetone ligand is chelating in all these complexes. Consequently, tetrahedral coordination about the zirconium atom is proposed.

Preparation and Characterisation of Organo-Thallium(III) N-(Alkyl, Cyclohexyl)dithiocarbamates

Abstract Some organometallic compounds of thallium(III) of the type (η5-Cp′)2T1(S2CNRR′) where Cp′ = cyclopentadienyl (C5H5), indenyl (C9H7, fluorenyl (C13H9); R = Me, Et, i-Pr and R′ = cyclohexyl (cyhx) have been prepared by the reaction of stoichiometric amounts of (η5-Cp′)2T1Br with sodium salts of dithiocarbamic acids in THF. Infrared spectral data indicates the bidentate nature of the dithiocarbamate groups. These complexes have been characterised on the basis of elemental analyses and conductance measurements as well as from their infrared and NMP spectra.