Rajendra Singh Ghadwal

Synthesis and Spectroscopic Characterisation of Six-Coordinate Complexes of Oxovanadium(V)

Complexes of the types VO(L)(R-deaH), VO(R-dea)(LH), and VO(L)(OGOH)[L = deprotonated form of N-(1-hydroxyethyl) naphthaldimine; R-dea = deprotonated form of a N-substituted diethanolamine, with R = H or Ph; G = CH2CH2, CHMeCHMe, CMe2CMe2, CHMeCH2CMe2, CMe2CH2CH2CMe2] have been prepared by the equimolar reactions of VO(OPri)3, LH2, and an appropriate diethanolamine or glycol in benzene. All of these coloured solid complexes have been characterised by elemental (C, H, N, and V) analyses and by spectroscopic (i.r., electronic, 1H-, 51V-n.m.r) studies. The relative lability of the hydroxy group(s) of N-(1-hydroxyethyl)naphthaldiamine, diethanolamine, and glycol has also been investigated.

Synthesis and spectroscopic properties of homo– and heterobimetallic complexes of oxovanadium (V)

Equimolar interaction of VO(OPri)3 with N-phenyldiethanolamine (H2L) affords the dimeric complex [VO(L)((μ-OPri)]2 (1), which on reaction with different glycols yields a new class of oxovanadium(V) complexes of the type: VO(L)(OGOH) (where L = C6H5N(CH2CH2O-)2 and G = G1 (CMe2CH2 CH2CMe2)2, G2(CHMeCH2CMe2)3, G3(CH2CMe2CH2)4, G4(CH2CEt2CH2)5, G5(CHMeCHMe)6, G6(CMe2CMe2)7), featuring 2N-phenyldiethanolaminate and glycolate moieties. Complexes (2)–(7) react with Al(OPri)3 to afford novel heterobimetallic coordination complexes of the type: VO(L)(OGO) Al(OPri)2 (G = G1-G6). All these complexes have been characterised by elemental analyses and molecular weight measurements. Spectroscopic (IR, UV-Vis and1H,27Al,51V) NMR) properties of the new complexes have been investigated and their plausible structures suggested.

Preparation and spectroscopic characterisation of a series of heterobimetallic N-phenyldiethanolaminate-alkoxide derivatives of oxovanadium(V)

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.

Homometallic glycolates containing hydroxyl functionality for anchoring another metal: synthesis and characterization of heterometallic alkoxide–glycolates of Ti and Zr incorporating Al and Nb

Abstract Reaction of Ti(OPri)4 with 2-methyl-2,4-pentanediol [HOGOH, where G = CMe2CH2CH(Me)] in 1 : 3 M ratio under reflux afforded the monomeric [Ti(OGO)(OGOH)2] (1), which on further reactions with [Al(OPri)3] or [Nb(OPri)5] in 1 : 1 and 1 : 2 M ratios afforded heterometallic derivatives, [Ti(OGO)3{M(OPri)n−2}] and [Ti(OGO)3{M(OPri)n−1}2] [where M = Al (n = 3), Nb (n = 5)], respectively. Similar reactions of Zr(OPri)4∙PriOH with a number of glycols [HOGOH, where G = CH(Me)CH(Me), CMe2CMe2, CMe2CH2CH(Me)] yielded dimeric [Zr2(OGO)2(OGOH)4]. [Zr2(OGO)6{M(OPri)n−2}2] and [Zr2(OGO)4(OGOH)2M(OPri)n−2] [M = Al (n = 3), Ti (n = 4), Nb (n = 5)] were prepared by 1 : 2 and 1 : 1 reactions, respectively, of [Zr2(OGO)2(OGOH)4] with Al(OPri)3, Ti(OPri)4, or Nb(OPri)5. Surprisingly, a 1 : 2 reaction of [VO(OPri)3] with 2,2-diethyl-1,3-propanediol in benzene followed a different reaction and produced a neutral tetranuclear derivative [V4(O)4(μ-OCH2CEt2CH2O)2(OCH2CEt2CH2O)4] (18). All of these derivatives were characterized by elemental analysis, molecular weight measurements, FT-IR, and 1H NMR (and wherever possible, by 27Al or 51V NMR) spectroscopic studies. The derivatives [Zr2(OCMe2CH2CH(Me)O)2(OCMe2CH2CH(Me)OH)4] (9 and 18) were additionally characterized by single-crystal X-ray structure analysis.

Synthesis and Spectroscopic Properties of the First Series of Heteronuclear Derivatives Containing Organosilicon/Organotin (IV) and Oxovanadium (V) Moieties

Me 3 SiCl reacts with [VO(OGO)(OGOH)] ( 1a ) or [VO(L)(LH)] ( 1b ) (where OGO = OCMe 2 CH 2 CH 2 CMe 2 O and L = OC 6 H 4 CH═NCH 2 -CH 2 O) in the presence of Et 3 N as a proton acceptor (1:1:1 stoichiometric ratio) in benzene to form heteronuclear derivatives [VO(OGO)(OGOSiMe 3 )] 2 ( 2 ) and [VO(L)(LSiMe 3 )] ( 3 ), respectively. The reactions of Bu 3 Sn(OPr i ) with a variety of oxovanadium(V) complexes ( 1a ), ( 1b ), and [VO(PhDEA)(PhDEAH)] ( 1c ) (in a 1:1 stoichiometric ratio, where PhDEA = C 6 H 6 N(CH 2 CH 2 O) 2 ) afford derivatives [VO(OGO)(OGOSnBu 3 )] 2 ( 4 ), [VO(L)(LSnBu 3 )] ( 5 ), and [VO(PhDEA)(PhDEASnBu 3 )] ( 6 ), respectively. Derivatives [(Ph 3 SiO) VO(OGO)] 2 ( 7 ) and [(Ph 3 SiO)VO(L)] ( 8 ) have been prepared by the equimolar reactions of Ph 3 SiOH with [VO(OGO)(OPr i )] ( 1d ) and [VO(L)(OPr i )] ( 1e ), respectively. All these new derivatives have been characterized by elemental analyses, molecular weight measurements, and spectroscopic [IR, NMR ( 1 H, 29 Si, 51 V, and 119 Sn)] studies.

Synthesis and spectroscopic characterisation of a new class of heterobimetallic homoleptic diethanolaminate complexes of niobium(V) and tantalum(V)

Nine heterobimetallic homoleptic diethanolaminate complexes of the types: [Nb(Rdea)3{Ta(Rdea)2}] (where Rdea = RN(CH2CH2O-)2 and R = H, 2; Me, 3; Bu n , 4; Ph, 5), [Nb(Rdea)3{Al(Rdea)}] (R = H, 6; Me, 7; Bu n , 8; Ph, 9), and [Nb(Phdea)3{Sb(Phdea)}] 10 have been prepared for the first time by the equimolar reactions of [Nb(Rdea)2(RdeaH)] with [Ta(Rdea)2(OPr i )] or [Al(Rdea)(OPr i )] or [Sb(Phdea)(OPr i )] in benzene. The structural features of the new complexes have been elucidated by IR and NMR (1H, 27Al) spectroscopies.