Indian Journal of Chemistry

Sect. A: Inorganic, Bio-inorganic, Physical, Theoretical & Analytical

Total visitors: 3,463  since 21-02-08

 

VOLUME 47A

NUMBER 2

February 2008

 

CONTENTS

 

Papers

 

181

 

Synthesis and characterization of Al-HMS catalysts and their application for t-butylation of toluene

 

 

 

 

 

 

 

 

 

 

Weihua Yu*, Chunhui Zhou, Deyi Lü, Bo Zhang & Xiangsheng Xu

 

 

 

 

Al-HMS catalysts with 2 - 10 mol % Al content have been synthesized using dodecylamine surfactant as template and aluminum s-butoxide as the aluminum source. These materials possess abundant tetrahedral aluminum in the HMS framework as well as Brönsted and Lewis acid sites. The catalytic activity of the materials has been tested in 4-t-butylation reaction of toluene in liquid phase. Maximum conversion (85.1%) of toluene has been achieved with 10%Al-HMS catalyst, while high selectivity
(> 80%) for 4-t-butyltoluene is observed over 2 - 4.8% Al-HMS catalysts.

 

 

186

 

Palladium catalysts doped in CexZr1-xO2 washcoated monoliths for toluene combustion

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Qingbao Zhang, Leihong Zhao*, Botao Teng, Mengfei Luo, Yunlong Xie & Lei Yue

 

 

 

 

Pd-CexZr1-xO2/monolith catalysts have been prepared with
CexZr1-xO2 as a novel washcoat. The washcoat shows excellent adhesion to the monolith. The Pd-Ce0.8Zr0.2O2/monolith catalyst exhibits the highest catalytic activity for toluene combustion. There is strong interaction amongst palladium, ceria-zirconia solid solution and the monolith. The interaction changes the redox property and influences the catalytic activity of the catalysts.

 

 

 

194

 

Effect of organic fuels on catalytic properties of La0.8Sr0.2CoO3 with large surface area

 

 

 

 

 

 

 

 

 

 

Wei Liu, Laitao* & Yuehui Wu

 

 

 

 

Perovskite-type La0.8Sr0.2CoO3 oxides have been prepared by solution combustion synthesis and their catalytic performance for CH4 combustion reaction has been studied. The effect of organic fuels on the structure and the catalytic activities of La0.8Sr0.2CoO3 catalysts has been investigated. Results indicate that all the La0.8Sr0.2CoO3 catalysts prepared by solution combustion synthesis have large specific surface area. The best catalytic activity is shown by the La0.8Sr0.2CoO3 catalyst prepared with
DL-alanine.

 

 

199

 

Electronic parameters of aliphatic hydrazides with AM1 and PM3 Hamiltonians

 

 

 

 

 

 

 

I Suryanarayana*, V Ananta Ramam,
K M M Krishna Prasad & R Sambasiva Rao

 

 

 

 

Optimized geometries and quantum chemically derived electronic parameters of physicochemical significance of mono- and di-aliphatic hydrazides have been investigated using AMPAC 6.7 package. Total energy and heat of formation show that the hydrazide fragments enhance the stability. The order of stability for different aliphatic acid hydrazides is: AdipHy > MalHy > OxalHy > AcetHy > FormHy. SEMO procedures with MNDO, AM1, PM3 and SAM1 Hamiltonians in gaseous phase reveal that the hydrazides participate in charge- and orbital- based interactions.

 

 

207

 

Syntheses, spectroscopic studies, crystal
structure and complexation reactions of
N- (2 or 4-hydroxylphenyl) benzaldimine

 

 

 

 

 

 

Rajib Lal De*, Mahuya Mandal, Lovely Roy & Jaydeep Mukherjee

 

 

 

 

Two monobasic bidentate Schiff base ligands, derived from the condensation reaction between benzaldehyde and 2-aminophenol or 4-aminophenol, have been subjected to complexation reactions, stabilising the bis-ligated complexes MII(SB)2 (MII=Cu, Ni, Co and Zn), where aminophenolic (-OH) groups participate in the complexation reaction. The newly synthesized Schiff bases and their complexes have been characterized by elemental analysis, magnetic, spectroscopic and electrochemical studies.

 

 

214

 

Template synthesis of Cu(II), Co(II), Fe(III), Mn(II), Zn(II) and Cd(II) complexes of 2-aminophenol in presence of 4-benzyloxybenzaldehyde and 2-butenal.

 

 

 

 

 

 

M B H Howlader*, M B Hossain & N Akhter

 

 

 

 

Reaction of 2-aminophenol with Cu(II), Co(II), Fe(III), Mn(II), Zn(II) and Cd(II) ions in presence of 4-benzyloxybenzaldehyde/  2-butenal yields the complexes [Cu(L)2], [Co(L)2(H2O)2], [Fe(L)2(H2O)Cl], [Mn(L)2(H2O)2], [Zn(L)2], [Cd(L)2], [Cu(L')2], [Co(L')2(H2O)2], [Fe(L')2(H2O)Cl], [Mn(L')2(H2O)2], [Zn(L')2] and [Cd(L')2], where L = C6H5CH2OC6H4CH=NC6H4O and
L' = CH3CHCHCH=NC6H4O. The complexes have been formed by template method and not via ligand formation.

 

Notes

 

220

 

Energy and Estrada index of phenylenes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Boris Furtula & Ivan Gutman*

 

 

 

 

The relationships between the energy, E, and the Estrada index, EE, of phenylenes and their hexagonal squeezes are examined. Within sets of isomers, a good linear correlation exists between E(phenylene) and E(hexagonal squeezes), as well as between EE(phenylene) and EE(hexagonal squeezes). Results show that an earlier obtained relationship between E(phenylene) and E(hexagonal squeezes) needs to be modified.

 

 

 

 

225

 

Symmetry of dimanganese decacarbonyl with D4d point group

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Ahmad Gholami* & Ali Reza Ashrafi

 

 

 

 

A simple method is described to calculate the automorphism group of weighted graphs. This method has been applied to compute the symmetry of dimanganese decacarbonyl with D4d point Group.

 

 

 

228

 

Synthesis and characterization of bulky aryloxides of germanium(IV) and tin(IV)

 

 

 

 

 

 

 

 

Manju Jindal (neé Goyal) & Anirudh Singh*

 

 

 

 

Seven sterically hindered aryloxides of germanium(IV) and tin(IV) have been prepared in quantitative yields by the metathesis reaction of germanium(IV)- and tin(IV)- chlorides. The compounds have been characterized by elemental analyses, molecular weight determinations and spectroscopic studies.

 

 

 

232

 

Oscillation parameters of mixed substrate system containing DL-malic acid and maleic acid in sulfuric acid medium

 

 

 

 

 

 

 

 

 

D Kumar, A Sinha & R N Upadhyay*

 

 

 

 

Belousov-Zhabotinsky reaction has been studied using
DL-malic acid and maleic acid in the form of mixed organic substrate in a batch reactor, with CeIV ions as catalyst and sulfuric acid as the medium. The oscillation parameters have been determined at different concentrations of DL-malic acid, maleic acid, CeIV ions and bromate and have been found to obey linear relationships. It has also been observed that lower the concentration of organic substrates, higher the total oscillatory period, while higher the concentration of bromate and catalyst, higher the total oscillatory period.

 

 

236

 

Computational studies and reactivity of nucleophiles in benzylation reactions

 

 

 

 

 

 

 

 

 

S. Ranga Reddy, P. Kalyani, B. Rajeswara Rao & P. Manikyamba*

 

 

 

 

The nucleophilic substitution reaction of benzyl bromide using
2-mercaptobenzimidazole, 2-mercaptobenzoxazole and
2-mercaptobenzothiazole as nucleophiles has been studied in methanol and acetone media. The higher reactivity of
2-mercaptobenzimidazole is attributed to the presence of two nitrogen atoms holding a pair of electrons on either side of the >C=S group. The heat of formation, DHf, computed from AM1 studies indicates that the reactivity of the nucleophiles is related to DHf, and HOMO-LUMO gap of the nucleophile.

 

 

240

 

Determination of pKa of ammonium and phenolic groups: Evidence of intramolecular hydrogen bonding in aqueous solution

 

 

 

 

 

 

 

 

 

 

 

 

 

Yoke-Leng Sim, Wan Hamdah Wan Ahmad,
Azhar Ariffin  & M Niyaz Khan*

 

 

 

 

The ionization constants of 2-hydroxyanilinium, 2-methoxy-anilinium, 4-nitroanilinium ions, N-(2'-hydroxyphenyl)phthalamic acid and N-(2'-methoxyphenyl)phthalamic acid, determined spectrophotometrically, have been rationalized in terms of internal hydrogen bonding and steric hindrance between o–substituent and reaction site.

 

 

 

 

246

 

Calix[6]arene derivative as chromogenic sensor for anti-hypertensive drugs

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S K Menon*, P Jose, U Harikrishnan & U Pal

 

 

 

 

Determination of some anti-hypertensive drugs via charge transfer complexation and hydrogen bonding with a novel chromogenic calyx[6]arene derivative is described.

 

 

 

Authors for correspondence are indicated by (*)


Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 181-185

 

Synthesis and characterization of Al-HMS catalysts and their application fort-butylation of toluene

Weihua Yu*, Chunhui Zhou, Deyi Lü, Bo Zhang & Xiangsheng Xu

Received 30 July 2007; revised 16 January 2008

Al-HMS (hexagonal mesoporous silica) with Al content in the range 2 - 10 mol% has been synthesized using dodecylamine surfactant as template and aluminum s-butoxide as the aluminum source. The mesoporous structure has been confirmed by XRD and the surface area and pore size calculated by BET equation and BJH method using nitrogen adsorption-desorption technique. The aluminum atom coordination has been determined by 27Al MAS NMR. The total acidity and the type of acid sites have been studied using TPD of chemisorbed 2,6-di-tert-butylpyridine and IR spectra of pyridine adsorption, respectively. The Al-HMS materials possess abundant tetrahedral aluminum in the HMS framework and also BrÖnsted and Lewis acid sites. The catalytic activities of the materials have been tested in 4-t-butylation reaction of toluene in liquid phase. Maximum conversion (85.1%) of toluene has been achieved with 10%Al-HMS catalyst, and high selectivity (> 80%) for 4-t-butyltoluene is observed over 2 - 4.8% Al-HMS catalysts. The conversion of toluene increases with increase of Al content, and the selectivity of 4-t-butyltoluene decreases to 70% when Al content is increased up to 10% in HMS materials.

IPC Code: Int. Cl.8 B01J21/00; B01J37/00

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 186-193

 

Palladium catalysts doped in CexZr1-xO2 washcoated monoliths for toluene combustion

 

Qingbao Zhang, Leihong Zhao*, Botao Teng, Mengfei Luo, Yunlong Xie & Lei Yue

Received 20 July 2007; revised 24 December 2007

A novel CexZr1-xO2 washcoat has been prepared by an impregnation method, which acts as a host for the active Pd component to prepare a series of the Pd-CexZr1-xO2/monolith (x=1, 0.8, 0.6 and 0.5) catalysts for toluene combustion. SEM, BET, XRD, Raman spectroscopy, and H2-TPR techniques have been used to characterize the samples. The washcoat shows excellent adhesion to the monolith. The Zr component of the Pd-CexZr1-xO2/monolith catalysts plays an important role in the catalytic activity for toluene combustion and the order of the catalytic activity is  x = 0.8>0.6>0.5≈1. There is strong interaction among palladium, ceria-zirconia solid solution and the monolith.

IPC Code: Int. Cl.8 B01J21/00; B01J37/00

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 194-198

 

Effect of organic fuels on catalytic properties of La0.8Sr0.2CoO3 with large surface area

Wei Liu, Laitao* & Yuehui Wu

Received 31 July 2007; revised 10 January 2008

Perovskite-type La0.8Sr0.2CoO3 oxides have been prepared by solution combustion synthesis and their catalytic performance for CH4 combustion reaction has been studied. The prepared samples have been characterized by XRD, IR, BET and TPR. The effects of organic fuels on the structure and the catalytic activities of La0.8Sr0.2CoO3 catalysts have been investigated. Results indicate that all the La0.8Sr0.2CoO3 catalysts prepared by solution combustion synthesis have large specific surface area, and the structure and catalytic activities of the catalysts are related to the organic fuels. The best catalytic activity ofis shown by the La0.8Sr0.2CoO3 catalyst prepared with DL-alanine. The activity of the catalyst can be explained in terms of smaller crystallite size, larger specific surface area, lower activation energy and more mobility of chemisorbed oxygen ion the surface and in the vacancies.

IPC Code: Int. Cl.8 B01J 21/00

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 199-206

 

Electronic parameters of aliphatic hydrazides with AM1 and PM3 Hamiltonians

I Suryanarayana*, V Ananta Ramam, & K M M Krishna Prasad  & R Sambasiva Rao

Received 24 October 2006; revised 12 December 2007

The optimized geometries and quantum chemically derived electronic parameters of physicochemical significance of mono- and di-aliphatic hydrazides are investigated using AMPAC 6.7 package. The number of hydrazide fragments enhances the stability as indicated by total energy and heat of formation. The partition of quantum chemical energy into its constituents is reported. The order of stability observed for different aliphatic acid hydrazides is: AdipHy > MalHy > OxalHy > AcetHy > FormHy. LUMO is on the second hydrazide fragment and HOMO as well as LUMO spread only on one of the fragments for dihydrazides with the exception for AdipHy. The shapes inferred from total electron density surface appear to be like banana for MalHy and nut (bent) for AdipHy. The negative charge on nitrogen of amino group is greater than that on oxygen of carbonyl and N of imino of hydrazide fragment. Linear (a) and third order (g) polarizabilities increase from monohydrazides to dihydrazides, but the total dipole moments show the trend as: MalHy > AcetHy > AdipHy > FormHy > OxalHy. The data relating to parameters of biological/physical relevance and chemical reactivity are reported. These results from SEMO procedures with MNDO, AM1, PM3 and SAM1 Hamiltonians in gaseous phase reveal that the hydrazides participate in charge and orbital-based interactions. The bond lengths, bond angles and dihedral angles are same for optimized geometry in a typical study by changing SCF convergence limits and different quasi Newton algorithms.

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 207-213

 

Syntheses, spectroscopic studies, crystal structure and complexation reactions of N- (2 or 4-hydroxylphenyl) benzaldimine

Rajib Lal De*, Mahuya Mandal, Lovely Roy & Jaydeep Mukherjee

Received 20 July 2007; revised 3 January 2008

Two monobasic bidentate Schiff base ligands (SBH) derived from the condensation reaction between benzaldehyde and 2-aminophenol (BENOPH) or 4-aminophenol (BENPAPH) have been subjected to complexation reactions stabilising the bis-ligated complexes MII(SB)2 (MII=Cu, Ni, Co and Zn) where aminophenolic (-OH) groups participate in the complexation reaction. The newly synthesized Schiff bases and their complexes are characterized by elemental analysis, magnetic, spectroscopic and electrochemical studies. Crystal structure studies performed on BENPAPH show it to crystallize in the monoclinic form, space group P21/c; Z=4 with a, 6.500(7); b, 14.885(3); c, 10.852(2) Å and β, 91.489(12)°.

IPC Code: Int. Cl.8 C07F1/08; C07F3/06; C07F15/04; C07F15/06

 

Indian Journal of Chemistry

Vol 47A, February 2008, pp. 214-219

 

Template synthesis of Cu(II), Co(II), Fe(III), Mn(II), Zn(II) and Cd(II) complexes of 2-aminophenol in presence of 4-benzyloxybenzaldehyde and 2-butenal

M B H Howlader*, M B Hossain & N Akhter

Received 22 August 2007; revised 8 January 2008

Reaction of 2-aminophenol with Cu(II), Co(II), Fe(III), Mn(II), Zn(II) and Cd(II) ions in presence of 4-benzyloxybenzaldehyde and 2-butenal yields the complexes [Cu(L)2] 1, [Co(L)2(H2O)2] 2, [Fe(L)2(H2O)Cl] 3, [Mn(L)2(H2O)2] 4, [Zn(L)2] 5, [Cd(L)2] 6, [Cu(L')2] 7, [Co(L')2(H2O)2] 8, [Fe(L')2(H2O)Cl] 9, [Mn(L')2(H2O)2] 10, [Zn(L')2] 11 and [Cd(L')2] 12 (where L = C6H5CH2OC6H4CH=NC6H4O and L' = CH3CHCHCH=NC6H4O). The complexes have been formed by template method, not via ligand formation. Complexes 1 and 7 are square planar, 2-4 and 8-10 are octahedral and 5-6 and 11-12 are tetrahedral in nature. Nickel(II) does not form complexes under the experimental condition. All the complexes are biologically active against six pathogenic bacteria (S. dysenteria, E. coli, P. aeruginosa, B. subtilis, S. lutea and S. aureus). Complexes 1, 2, 6, 9, 10, 11 and 12 show good activity as compared to the ligand precursor, 2-aminophenol., with cComplex 10 showing the best activity (MIC of complex 10 = 16 μg/mL for S. dysenteria and  B. subtilies).

IPC Code: Int. Cl.8 C07F1/08; C07F3/06; C07F3/08; C07F15/02; C07F15/06; C07F13/00

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 220-224

 

Energy and Estrada index of phenylenes

Boris Furtula & Ivan Gutman*

Received 4 October 2007; revised 15 January 2008

In the theory of polycyclic conjugated molecules, several remarkable results are known relating the properties of a phenylene with the analogous properties of a benzenoid molecule that in a natural way is associated with PH, called the hexagonal squeeze (HS) (for details see Fig. 1 or ref. 2). In the present work, the relationships between the energy, E, and the Estrada index, EE, of phenylenes and their hexagonal squeezes are examined. Within sets of isomers, a good linear correlation exists between E(phenylene) and E(hexagonal squeeze), as well as between EE(phenylene) and EE(hexagonal squeeze). The details of these correlations are established. Results show that an earlier obtained relationship between E(phenylene) and E(hexagonal squeeze) needs to be modified.

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 225-227

 

Symmetry of dimanganese decacarbonyl with D4d point group

Ahmad Gholami* & Ali Reza Ashrafi

Received 8 August 2007; revised 21 December 2007

Let G be a weighted graph with the adjacency matrix A = [aij]. An Euclidean graph associated to a molecule is defined by a weighted graph with the adjacency matrix D = [dij], where for i ¹ j, dij is the Euclidean distance between the nuclei i and j. In this matrix dii can be taken as zero if all the nuclei are equivalent. Otherwise, one may introduce different weights for different nuclei. Balasubramanian computed the Euclidean graphs and its automorphism groups for benzene, eclipsed and staggered forms of ethane and eclipsed and staggered forms of ferrocene (Chem Phys Lett, 232 (1995) 415-423). In this work, a simple method is described by means of which it is possible to calculate the automorphism group of weighted graphs. We apply this method to compute the symmetry of dimanganese decacarbonyl with D4d point group.

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 228-231

 

Synthesis and characterization of bulky aryloxides of germanium(IV) and tin(IV)

Manju Jindal (neé Goyal) & Anirudh Singh*

Received 20 June 2007; revised 10 January 2008

Seven sterically hindered aryloxides of germanium(IV) and tin(IV) have been prepared in quantitative yields by the metathesis reactions of germanium(IV)- and tin(IV)- chlorides, and characterized by elemental analyses, molecular weight determinations and spectroscopic studies.

IPC Code: Int. Cl.8  C07F7/22; C07F7/30

 

Indian Journal of Chemistry

Vol 47A, February 2008, pp. 232-235

 

Oscillation parameters of mixed substrate system containing DL-malic acid and maleic acid in sulfuric acid medium

D Kumar, A Sinha & R N Upadhyay*

Received 12 November 2006; re-revised 17 January 2008

Belousov-Zhabotinsky reaction has been studied usingDL-malic acid and maleic acid in the form of mixed organic substrate in a batch reactor. CeIV ions have been used as catalyst and sulfuric acid as the medium. The oscillation parameters have been determined at different concentrations of DL-malic acid, maleic acid, CeIV ions and bromate. The oscillation parameters have been found to obey linear relationships. It has also been observed that lower the concentration of organic substrates, higher the total oscillatory period, while higher the concentration of bromate and catalyst, higher the total oscillatory period.

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 236-239

 

Computational studies and reactivity of nucleophiles in benzylation reactions

S. Ranga Reddy, P. Kalyani, B. Rajeswara Rao & P. Manikyamba*

Received 1 February 2007; revised 16 January 2008

The nucleophilic substitution reactions of benzyl bromide using 2-mercapto benzimidazole, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole as nucleophiles have been studied in methanol and acetone media. The higher reactivity of 2-mercaptobenzimidazole is attributed to the presence of two nitrogen atoms holding a pair of electrons on either side of the >C=S group. The heats of formation, DHf, computed from AM1 studies indicates that the reactivity of the nucleophiles is related to DHf, and HOMO-LUMO gap of the nucleophile.

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 240-245

 

Determination of pKa of ammonium and phenolic groups: Evidence of intramolecular hydrogen bonding in aqueous solution

Yoke-Leng Sim, Wan Hamdah Wan Ahmad, Azhar Ariffin  & M Niyaz Khan*

Received 16 April 2007; revised 4 January 2008

The ionization constants of 2-hydroxyanilinium, 2-methoxyanilinium, 4-nitroanilinium ions, N-(2′-hydroxyphenyl)-phthalamic acid and N-(2′-methoxyphenyl) phthalamic acid, determined spectrophotometrically, have been rationalized in terms of internal hydrogen bonding and steric hindrance between o–substituent and reaction site.

 

Indian Journal of Chemistry

Vol. 47A, February 2008, pp. 246-250

 

Calix[6]arene derivative as chromogenic sensor for anti-hypertensive drugs

S K Menon*, P Jose, U Harikrishnan & U Pal

Received 26 February 2007; revised 22 December 2007

A simple, rapid, and sensitive spectrophotometric method has been developed for the determination of atenolol, propranolol hydrochloride and metaprolol tartarate. The method is based on the reaction of these drugs as n-electron donors with acceptor groups on macrocyclic ring of calixarene. Due to the rapid development of color at ambient temperatures, the chromogenic calix[6]arene derivative can be used for the determination of these b-adrenergic blocking drugs. The association constants (KcD) and free energies for the complexes have been determined. The proposed method can be used to determine the drugs in pharmaceutical tablets and urine.

IPC Code: Int. Cl.8 G01N21/00