Biswajit Deb - Academia.edu (original) (raw)
Papers by Biswajit Deb
Journal of Coordination Chemistry, 2018
The polymeric precursor [RuCl 2 (CO) 2 ] n reacts with the ligands, PP (a,b) and PO (c,d), in 1... more The polymeric precursor [RuCl 2 (CO) 2 ] n reacts with the ligands, PP (a,b) and PO (c,d), in 1:1 molar ratio to generate six-coordinate complexes [RuCl 2 (CO) 2 (ƞ 2-PP)] (1a, 1b) and [RuCl 2 (CO) 2 (ƞ 2-PO)] (1c, 1d), where PP: Ph 2 P(CH 2) n PPh 2 , n = 2(a), 3(b); PO: Ph 2 P(CH 2) n P(O)Ph 2 , n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR and NMR spectroscopy. 1a-1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75-290 h-1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl 3 itself. Among 1a-1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogues (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b and 1d decrease considerably, while 1c shows similar activity during the second run.
Coordination Chemistry Reviews, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit:
Polyhedron, 2009
The reaction of xantphos dioxide (O\O) with the polynuclear precursor [Ru(CO) 2 Cl 2 ] n to give ... more The reaction of xantphos dioxide (O\O) with the polynuclear precursor [Ru(CO) 2 Cl 2 ] n to give the mononuclear complex [Ru(CO) 2 Cl 2 (O\O)](1) is reported together with single crystal X-ray structure analyses of both the free ligand and the ruthenium complex. The synthesized compounds have also been characterized by elemental analyses, IR and NMR (1 H, 31 P and 13 C) spectroscopy. The ligand O\O crystallizes with lattice water molecules in a triclinic system with space group P 1 whereas the complex 1 crystallizes in an orthorhombic system with space group P2 1 2 1 2 1. Each mononuclear unit of O\O and 1 is stabilized in their solid state through non-covalent (C-HÁÁÁO, C-HÁÁÁCl and C-HÁÁÁp) interactions to develop an extended three-dimensional network structure. The complex 1 exhibits an interesting intramolecular OÁÁÁO interaction between one of the P@O groups and backbone O leading to different electron donacity of two P@O groups to the metal centre.
![Research paper thumbnail of Synthesis, characterisation and thermal studies of ruthenium(II) carbonyl complexes of functionalised tripodal phosphine chalcogen donor ligands, [CH3C(CH2P(X)Ph2)3], where X=Se, S, O](https://attachments.academia-assets.com/103375717/thumbnails/1.jpg)
](Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009
The polymeric ruthenium(II) carbonyl complex, [Ru(CO) 2 Cl 2 ] n reacts with 1,1,1-tris-(diphenyl... more The polymeric ruthenium(II) carbonyl complex, [Ru(CO) 2 Cl 2 ] n reacts with 1,1,1-tris-(diphenylphosphinomethyl)ethane trichalcogenide ligands, [CH 3 C(CH 2 P(X)Ph 2) 3 ], where X = Se(a), S(b) and O(c) in 1:1 (metal:ligand) molar ratio to afford hexa-coordinated complexes of the type 2-(X,X)-[Ru(CO) 2 Cl 2 P 3 X 3 ] (1a-c). The complexes 1a-c exhibit two equally intense (CO) bands in the range 1979-2060 cm −1 indicating cis-disposition of the two terminal carbonyl groups. The values of (CO) frequencies containing different ligands, in general, follow the order: P 3 O 3 > P 3 S 3 > P 3 Se 3 which may be explained in terms of 'Soft-Hard' (Ru(II)-O) and 'Soft-Soft' (Ru(II)-S/Se) interactions. The complexes have been characterized by elemental analyses, mass, 1 H, 31 P, 77 Se and 13 C NMR spectroscopy. The thermal stability of the complexes has also been studied.
![Research paper thumbnail of Rhodium(I) carbonyl complexes of tetradentate chalcogen functionalized phosphines, [P′(X)(CH2CH2P(X)Ph2)3] {X = O, S, Se}: Synthesis, reactivity and catalytic carbonylation reaction](https://attachments.academia-assets.com/103375716/thumbnails/1.jpg)
](Journal of Organometallic Chemistry, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright CORE Metadata, citation and similar papers at core.ac.uk
Journal of Organometallic Chemistry, 2012
New palladium complexes of the type [PdCl 2 (h 2 ePXP)] (1a,1b) and [PdCl 2 (h 2 ePXS)] (1c,1d) h... more New palladium complexes of the type [PdCl 2 (h 2 ePXP)] (1a,1b) and [PdCl 2 (h 2 ePXS)] (1c,1d) have been synthesised by the reaction of PdCl 2 with P,P and P,S type bidentate ligands in 1:1 mol ratio, where, PXP ¼ 9,9edimethyl-4,5-bis(diphenylphosphanyl) xanthene {Xantphos}(a) or bis(2-diphenylphosphanylphenyl)ether{DPEphos}(b); PXS ¼ 9,9-dimethyl-4,5-bis(diphenyl-phosphanyl) xanthenemonosulfide {Xantphos(S)}(c) or bis(2-diphenylphosphanyl phenyl) ether monosulfide {DPEphos(S)}(d). The complexes are characterized by elemental analyses, mass spectrometry, 1 H, 13 C and 31 P NMR spectroscopy together with the single crystal X-ray structure determination of 1a and 1d. The palladium atom in all the complexes occupies the centre of a slightly distorted square planar environment formed by a P atom, a P/S atom and two Cl atoms. The catalytic activities of 1ae1d investigated for SuzukieMiyaura cross-coupling reactions at room temperature exhibit higher yield of the coupling products than catalysed by PdCl 2 itself. Among 1ae1d, the palladium complexes of bidentate phosphine (1a, 1b) show higher efficacy than their monosulfide analogues (1c, 1d). However, the recycling experiments with the catalysts for a selected coupling reaction between 4-bromobenzonitrile and phenylboronic acid exhibit that 1c and 1d are more efficient than 1a and 1b, which may be due to the donor effect of the P,S ligands during catalytic reaction.
Journal of Molecular Catalysis A: Chemical, 2012
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are
Journal of Molecular Catalysis A: Chemical, 2009
The chemistry of phosphines and their derivatives have aroused much interest in the last few deca... more The chemistry of phosphines and their derivatives have aroused much interest in the last few decades because of their reactivity, structural novelty and catalytic activity [1], [2], [3], [4] and [5]. The tripodal polyphosphines such as CH 3 C(CH 2 PPh 2 ) 3 (triphos), have been ...
Journal of Molecular Catalysis A: Chemical, 2010
Oxidative addition to organometallic compounds is one of the key elementary steps in many catalyt... more Oxidative addition to organometallic compounds is one of the key elementary steps in many catalytic processes. For this reason, the reaction has been extensively studied, and in the last few years many publications have appeared concerning its implication to ...
Journal of Molecular Catalysis A: Chemical, 2009
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
Journal of Molecular Catalysis A: Chemical, 2008
Reaction of dimeric complex [Rh(CO) 2 Cl] 2 with two molar equivalent of pyridine alcohol ligands... more Reaction of dimeric complex [Rh(CO) 2 Cl] 2 with two molar equivalent of pyridine alcohol ligands (L) like 2-hydroxymethylpyridine (a), 3-hydroxymethylpyridine (b) and 4-hydroxymethylpyridine (c) afford the rhodium(I) dicarbonyl complexes [Rh(CO) 2 ClL](1a-c). The ligands are coordinated to the metal center through N-donor site. The complexes 1 undergo oxidative addition (OA) reactions with various alkyl halides (RI) like CH 3 I, C 2 H 5 I to produce Rh(III) complexes of the type [Rh(CO)(COR)IClL], where R =-CH 3 (2),-C 2 H 5 (3). Kinetic data for the reaction of 1 with CH 3 I indicate a first order reaction. The catalytic activity of the complexes 1 in the carbonylation of methanol was higher than that of the well known species [Rh(CO) 2 I 2 ] − .
Journal of Molecular Catalysis A: Chemical, 2010
The rhodium chemistry towards the activation of small molecules like CH 3 I, H 2 , I 2 , etc., an... more The rhodium chemistry towards the activation of small molecules like CH 3 I, H 2 , I 2 , etc., and their direct implications in various catalytic reactions such as carbonylation of alcohols, hydroformylation of alkenes, etc., are of great importance for academic as well as industrial interest [1], [2] ...
Journal of Molecular Catalysis A: Chemical, 2013
The dimeric rhodium precursor [Rh(CO) 2 Cl] 2 reacts with the ligands (L) quinoline-2-carboxylic ... more The dimeric rhodium precursor [Rh(CO) 2 Cl] 2 reacts with the ligands (L) quinoline-2-carboxylic acid (a) or quinoline-8-carboxylic acid (b) in 1:2 mole ratio to afford complexes of the type cis-[Rh(CO) 2 ClL] (1a and 1b). The complexes have been characterized by elemental analysis, Mass spectrometry, FT-IR and NMR (1 H, 13 C) spectroscopy. 1a and 1b undergo oxidative addition (OA) with different electrophiles such as CH 3 I, C 2 H 5 I and I 2 to give Rh(III) complexes of the type [Rh(CO)(COR)ClIL] {R = CH 3 (2a and 2b), R = C 2 H 5 (3a and 3b)} and [Rh(CO)ClI 2 L] (4a and 4b) respectively. OA of the CH 3 I with 1a forms relatively stable acyl intermediate which is evident from IR spectroscopy. The complexes 1a and 1b show higher catalytic activity for carbonylation of methanol to acetic acid and methyl acetate [Turn over number (TON) upto 1775 in 1 h] compared to that of the well known Monsanto's species [Rh(CO) 2 I 2 ] − (TON = 1000 in 1 h) under the reaction conditions: temperature 130 ± 2 • C, pressure 30 ± 2 bar, 450 rpm and 1 h reaction time.
Journal of Molecular Catalysis A: Chemical, 2014
Inorganica Chimica Acta, 2010
Transition metal complexes of rhodium and iridium containing different types of mono-and multi-de... more Transition metal complexes of rhodium and iridium containing different types of mono-and multi-dentate ligands have gained much importance because of their reactivity, structural novelty and catalytic applications [1], [2], [3], [4], [5], [6] and [7]. OA reactions of alkyl halides to ...
Inorganic Chemistry Communications, 2009
The hexa-coordinated chelate complexes of the type [Ru(CO) 2 Cl 2 (P-P)](1a,b) [where P-P = 9,9-d... more The hexa-coordinated chelate complexes of the type [Ru(CO) 2 Cl 2 (P-P)](1a,b) [where P-P = 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene(a) and [bis(2-diphenylphosphinophenyl)ether(b)] have been synthesized by reacting the polymeric precursor [Ru(CO) 2 Cl 2 ] n with the ligands in 1:1 molar ratio. The complexes 1a,b are characterized by elemental analyses, Mass, IR and NMR spectroscopy together with the single crystal X-ray structure determination of 1a. The compound 1a crystallizes in a monoclinic system with space group C2/c showing a slightly distorted octahedral geometry around the Ru centre. The complexes 1a and 1b are thermally stable up to 300°C and exhibit high catalytic activity in transfer hydrogenation of aldehyde and ketones to corresponding alcohols. The complexes 1a and 1b show much higher catalytic activity for the hydrogenation of aldehyde than ketones. In general, the catalytic efficiency of 1b is higher compared with 1a.
![Research paper thumbnail of Electron‐Rich Vaska‐Type Complexes trans ‐[Ir(CO)Cl(2‐Ph 2 PC 6 H 4 COOMe) 2 ] and trans ‐[Ir(CO)Cl(2‐Ph 2 PC 6 H 4 OMe) 2 ]: Synthesis, Characterisation and Reactivity](https://attachments.academia-assets.com/103375712/thumbnails/1.jpg)
](European Journal of Inorganic Chemistry, 2011
The in-situ-generated dimeric precursor [Ir(CO) 2 Cl] 2 reacts with four molar equivalents of the... more The in-situ-generated dimeric precursor [Ir(CO) 2 Cl] 2 reacts with four molar equivalents of the ligands 2-Ph 2 PC 6 H 4-COOMe (a) and 2-Ph 2 PC 6 H 4 OMe (b) to afford tetracoordinated complexes of the type trans-[Ir(CO)ClL 2 ] (1a, 1b), where L = a and b. The IR spectra of 1a and 1b in CHCl 3 solution show the terminal υ(CO) bands at around 1957 and 1959 cm-1 , respectively, which are significantly lower in frequency compared to Vaska's complex, trans-[Ir(CO)Cl-(PPh 3) 2 ] (1965 cm-1) and substantiate the enhanced electron density at the metal centre. The single-crystal X-ray structure of 1a indicates iridium-oxygen (ester group) distances [Ir•••O(2) 3.24 Å, Ir•••O(5) 3.29 Å] and angle [O(5)•••Ir•••O(2) 157.25°] suggesting a long-range intramolecular "second-[a] Materials Science Division,
European Journal of Inorganic Chemistry, 2010
The reaction of P,S-chelating diphosphane ligands [bis(2-diphenylphosphanylphenyl)ether monosulfi... more The reaction of P,S-chelating diphosphane ligands [bis(2-diphenylphosphanylphenyl)ether monosulfide] (a) and [9,9-dimethyl-4,5-bis(diphenylphosphanyl)xanthene monosulfide] (b) with [Ru(CO) 2 Cl 2 ] n in a 1:1 molar ratio affords two new ruthenium(II) complexes of the type [Ru(CO) 2 Cl 2 (PʝS)] (1a, 1b), where PʝS = a, b. The compounds are characterized by elemental analyses, mass spectrometry, thermal studies, and IR and NMR spectroscopy, together with single-crystal X-ray structure determination of bis(2-diphenylphosphanylphenyl)ether (DPEphos), a, 1a, and 1b. The ruthenium atom in both 1a and 1b occupies the center of a slightly distorted octahedral environment formed by a P atom, an S atom, two Cl atoms, and two CO groups. The crystal structures of a and 1a highlights an interesting feature, in which the P(2)-P(1)
Inorganica Chimica Acta, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
Journal of Coordination Chemistry, 2018
The polymeric precursor [RuCl 2 (CO) 2 ] n reacts with the ligands, PP (a,b) and PO (c,d), in 1... more The polymeric precursor [RuCl 2 (CO) 2 ] n reacts with the ligands, PP (a,b) and PO (c,d), in 1:1 molar ratio to generate six-coordinate complexes [RuCl 2 (CO) 2 (ƞ 2-PP)] (1a, 1b) and [RuCl 2 (CO) 2 (ƞ 2-PO)] (1c, 1d), where PP: Ph 2 P(CH 2) n PPh 2 , n = 2(a), 3(b); PO: Ph 2 P(CH 2) n P(O)Ph 2 , n = 2(c), 3(d). The complexes are characterized by elemental analyses, mass spectrometry, thermal studies, IR and NMR spectroscopy. 1a-1d are active in catalyzed transfer hydrogenation of acetophenone and its derivatives to corresponding alcohols with turnover frequency (TOF) of 75-290 h-1. The complexes exhibit higher yield of hydrogenation products than catalyzed by RuCl 3 itself. Among 1a-1d, the Ru(II) complexes of bidentate phosphine (1a, 1b) show higher efficiency than their monoxide analogues (1c, 1d). However, the recycling experiments with the catalysts for hydrogenation of 4-nitroacetophenone exhibit a different trend in which the catalytic activities of 1a, 1b and 1d decrease considerably, while 1c shows similar activity during the second run.
Coordination Chemistry Reviews, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit:
Polyhedron, 2009
The reaction of xantphos dioxide (O\O) with the polynuclear precursor [Ru(CO) 2 Cl 2 ] n to give ... more The reaction of xantphos dioxide (O\O) with the polynuclear precursor [Ru(CO) 2 Cl 2 ] n to give the mononuclear complex [Ru(CO) 2 Cl 2 (O\O)](1) is reported together with single crystal X-ray structure analyses of both the free ligand and the ruthenium complex. The synthesized compounds have also been characterized by elemental analyses, IR and NMR (1 H, 31 P and 13 C) spectroscopy. The ligand O\O crystallizes with lattice water molecules in a triclinic system with space group P 1 whereas the complex 1 crystallizes in an orthorhombic system with space group P2 1 2 1 2 1. Each mononuclear unit of O\O and 1 is stabilized in their solid state through non-covalent (C-HÁÁÁO, C-HÁÁÁCl and C-HÁÁÁp) interactions to develop an extended three-dimensional network structure. The complex 1 exhibits an interesting intramolecular OÁÁÁO interaction between one of the P@O groups and backbone O leading to different electron donacity of two P@O groups to the metal centre.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2009
The polymeric ruthenium(II) carbonyl complex, [Ru(CO) 2 Cl 2 ] n reacts with 1,1,1-tris-(diphenyl... more The polymeric ruthenium(II) carbonyl complex, [Ru(CO) 2 Cl 2 ] n reacts with 1,1,1-tris-(diphenylphosphinomethyl)ethane trichalcogenide ligands, [CH 3 C(CH 2 P(X)Ph 2) 3 ], where X = Se(a), S(b) and O(c) in 1:1 (metal:ligand) molar ratio to afford hexa-coordinated complexes of the type 2-(X,X)-[Ru(CO) 2 Cl 2 P 3 X 3 ] (1a-c). The complexes 1a-c exhibit two equally intense (CO) bands in the range 1979-2060 cm −1 indicating cis-disposition of the two terminal carbonyl groups. The values of (CO) frequencies containing different ligands, in general, follow the order: P 3 O 3 > P 3 S 3 > P 3 Se 3 which may be explained in terms of 'Soft-Hard' (Ru(II)-O) and 'Soft-Soft' (Ru(II)-S/Se) interactions. The complexes have been characterized by elemental analyses, mass, 1 H, 31 P, 77 Se and 13 C NMR spectroscopy. The thermal stability of the complexes has also been studied.
Journal of Organometallic Chemistry, 2011
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright CORE Metadata, citation and similar papers at core.ac.uk
Journal of Organometallic Chemistry, 2012
New palladium complexes of the type [PdCl 2 (h 2 ePXP)] (1a,1b) and [PdCl 2 (h 2 ePXS)] (1c,1d) h... more New palladium complexes of the type [PdCl 2 (h 2 ePXP)] (1a,1b) and [PdCl 2 (h 2 ePXS)] (1c,1d) have been synthesised by the reaction of PdCl 2 with P,P and P,S type bidentate ligands in 1:1 mol ratio, where, PXP ¼ 9,9edimethyl-4,5-bis(diphenylphosphanyl) xanthene {Xantphos}(a) or bis(2-diphenylphosphanylphenyl)ether{DPEphos}(b); PXS ¼ 9,9-dimethyl-4,5-bis(diphenyl-phosphanyl) xanthenemonosulfide {Xantphos(S)}(c) or bis(2-diphenylphosphanyl phenyl) ether monosulfide {DPEphos(S)}(d). The complexes are characterized by elemental analyses, mass spectrometry, 1 H, 13 C and 31 P NMR spectroscopy together with the single crystal X-ray structure determination of 1a and 1d. The palladium atom in all the complexes occupies the centre of a slightly distorted square planar environment formed by a P atom, a P/S atom and two Cl atoms. The catalytic activities of 1ae1d investigated for SuzukieMiyaura cross-coupling reactions at room temperature exhibit higher yield of the coupling products than catalysed by PdCl 2 itself. Among 1ae1d, the palladium complexes of bidentate phosphine (1a, 1b) show higher efficacy than their monosulfide analogues (1c, 1d). However, the recycling experiments with the catalysts for a selected coupling reaction between 4-bromobenzonitrile and phenylboronic acid exhibit that 1c and 1d are more efficient than 1a and 1b, which may be due to the donor effect of the P,S ligands during catalytic reaction.
Journal of Molecular Catalysis A: Chemical, 2012
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are
Journal of Molecular Catalysis A: Chemical, 2009
The chemistry of phosphines and their derivatives have aroused much interest in the last few deca... more The chemistry of phosphines and their derivatives have aroused much interest in the last few decades because of their reactivity, structural novelty and catalytic activity [1], [2], [3], [4] and [5]. The tripodal polyphosphines such as CH 3 C(CH 2 PPh 2 ) 3 (triphos), have been ...
Journal of Molecular Catalysis A: Chemical, 2010
Oxidative addition to organometallic compounds is one of the key elementary steps in many catalyt... more Oxidative addition to organometallic compounds is one of the key elementary steps in many catalytic processes. For this reason, the reaction has been extensively studied, and in the last few years many publications have appeared concerning its implication to ...
Journal of Molecular Catalysis A: Chemical, 2009
This article appeared in a journal published by Elsevier. The attached copy is furnished to the a... more This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright
Journal of Molecular Catalysis A: Chemical, 2008
Reaction of dimeric complex [Rh(CO) 2 Cl] 2 with two molar equivalent of pyridine alcohol ligands... more Reaction of dimeric complex [Rh(CO) 2 Cl] 2 with two molar equivalent of pyridine alcohol ligands (L) like 2-hydroxymethylpyridine (a), 3-hydroxymethylpyridine (b) and 4-hydroxymethylpyridine (c) afford the rhodium(I) dicarbonyl complexes [Rh(CO) 2 ClL](1a-c). The ligands are coordinated to the metal center through N-donor site. The complexes 1 undergo oxidative addition (OA) reactions with various alkyl halides (RI) like CH 3 I, C 2 H 5 I to produce Rh(III) complexes of the type [Rh(CO)(COR)IClL], where R =-CH 3 (2),-C 2 H 5 (3). Kinetic data for the reaction of 1 with CH 3 I indicate a first order reaction. The catalytic activity of the complexes 1 in the carbonylation of methanol was higher than that of the well known species [Rh(CO) 2 I 2 ] − .
Journal of Molecular Catalysis A: Chemical, 2010
The rhodium chemistry towards the activation of small molecules like CH 3 I, H 2 , I 2 , etc., an... more The rhodium chemistry towards the activation of small molecules like CH 3 I, H 2 , I 2 , etc., and their direct implications in various catalytic reactions such as carbonylation of alcohols, hydroformylation of alkenes, etc., are of great importance for academic as well as industrial interest [1], [2] ...
Journal of Molecular Catalysis A: Chemical, 2013
The dimeric rhodium precursor [Rh(CO) 2 Cl] 2 reacts with the ligands (L) quinoline-2-carboxylic ... more The dimeric rhodium precursor [Rh(CO) 2 Cl] 2 reacts with the ligands (L) quinoline-2-carboxylic acid (a) or quinoline-8-carboxylic acid (b) in 1:2 mole ratio to afford complexes of the type cis-[Rh(CO) 2 ClL] (1a and 1b). The complexes have been characterized by elemental analysis, Mass spectrometry, FT-IR and NMR (1 H, 13 C) spectroscopy. 1a and 1b undergo oxidative addition (OA) with different electrophiles such as CH 3 I, C 2 H 5 I and I 2 to give Rh(III) complexes of the type [Rh(CO)(COR)ClIL] {R = CH 3 (2a and 2b), R = C 2 H 5 (3a and 3b)} and [Rh(CO)ClI 2 L] (4a and 4b) respectively. OA of the CH 3 I with 1a forms relatively stable acyl intermediate which is evident from IR spectroscopy. The complexes 1a and 1b show higher catalytic activity for carbonylation of methanol to acetic acid and methyl acetate [Turn over number (TON) upto 1775 in 1 h] compared to that of the well known Monsanto's species [Rh(CO) 2 I 2 ] − (TON = 1000 in 1 h) under the reaction conditions: temperature 130 ± 2 • C, pressure 30 ± 2 bar, 450 rpm and 1 h reaction time.
Journal of Molecular Catalysis A: Chemical, 2014
Inorganica Chimica Acta, 2010
Transition metal complexes of rhodium and iridium containing different types of mono-and multi-de... more Transition metal complexes of rhodium and iridium containing different types of mono-and multi-dentate ligands have gained much importance because of their reactivity, structural novelty and catalytic applications [1], [2], [3], [4], [5], [6] and [7]. OA reactions of alkyl halides to ...
Inorganic Chemistry Communications, 2009
The hexa-coordinated chelate complexes of the type [Ru(CO) 2 Cl 2 (P-P)](1a,b) [where P-P = 9,9-d... more The hexa-coordinated chelate complexes of the type [Ru(CO) 2 Cl 2 (P-P)](1a,b) [where P-P = 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene(a) and [bis(2-diphenylphosphinophenyl)ether(b)] have been synthesized by reacting the polymeric precursor [Ru(CO) 2 Cl 2 ] n with the ligands in 1:1 molar ratio. The complexes 1a,b are characterized by elemental analyses, Mass, IR and NMR spectroscopy together with the single crystal X-ray structure determination of 1a. The compound 1a crystallizes in a monoclinic system with space group C2/c showing a slightly distorted octahedral geometry around the Ru centre. The complexes 1a and 1b are thermally stable up to 300°C and exhibit high catalytic activity in transfer hydrogenation of aldehyde and ketones to corresponding alcohols. The complexes 1a and 1b show much higher catalytic activity for the hydrogenation of aldehyde than ketones. In general, the catalytic efficiency of 1b is higher compared with 1a.
European Journal of Inorganic Chemistry, 2011
The in-situ-generated dimeric precursor [Ir(CO) 2 Cl] 2 reacts with four molar equivalents of the... more The in-situ-generated dimeric precursor [Ir(CO) 2 Cl] 2 reacts with four molar equivalents of the ligands 2-Ph 2 PC 6 H 4-COOMe (a) and 2-Ph 2 PC 6 H 4 OMe (b) to afford tetracoordinated complexes of the type trans-[Ir(CO)ClL 2 ] (1a, 1b), where L = a and b. The IR spectra of 1a and 1b in CHCl 3 solution show the terminal υ(CO) bands at around 1957 and 1959 cm-1 , respectively, which are significantly lower in frequency compared to Vaska's complex, trans-[Ir(CO)Cl-(PPh 3) 2 ] (1965 cm-1) and substantiate the enhanced electron density at the metal centre. The single-crystal X-ray structure of 1a indicates iridium-oxygen (ester group) distances [Ir•••O(2) 3.24 Å, Ir•••O(5) 3.29 Å] and angle [O(5)•••Ir•••O(2) 157.25°] suggesting a long-range intramolecular "second-[a] Materials Science Division,
European Journal of Inorganic Chemistry, 2010
The reaction of P,S-chelating diphosphane ligands [bis(2-diphenylphosphanylphenyl)ether monosulfi... more The reaction of P,S-chelating diphosphane ligands [bis(2-diphenylphosphanylphenyl)ether monosulfide] (a) and [9,9-dimethyl-4,5-bis(diphenylphosphanyl)xanthene monosulfide] (b) with [Ru(CO) 2 Cl 2 ] n in a 1:1 molar ratio affords two new ruthenium(II) complexes of the type [Ru(CO) 2 Cl 2 (PʝS)] (1a, 1b), where PʝS = a, b. The compounds are characterized by elemental analyses, mass spectrometry, thermal studies, and IR and NMR spectroscopy, together with single-crystal X-ray structure determination of bis(2-diphenylphosphanylphenyl)ether (DPEphos), a, 1a, and 1b. The ruthenium atom in both 1a and 1b occupies the center of a slightly distorted octahedral environment formed by a P atom, an S atom, two Cl atoms, and two CO groups. The crystal structures of a and 1a highlights an interesting feature, in which the P(2)-P(1)
Inorganica Chimica Acta, 2011
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