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Reaction of titanium (IV) chloride with oxalic and succinic acids
Notes
1{)45
A c k n o w l e d g e m e n t - S u p p o r t received for this investigation under contract DA-31-124-ARO(D)-35 is gratefully acknowledged. T. H. C H A N G * T H E R A D MOELLER¢
Noyes Chemical Laboratory University o f Illinois Urbana, Ill. 61801 U.S wt .
C H R I S T O P H E R W. ALLEN
Department o f Chemistry University o f Vermont Burlington, Vermont 05401 U.S.A.
* Present address: Department of Chemistry, National Taiwan University, Taipei, Taiwan. t Present address; Department of Chemistry, Arizona State University, Tempe, Arizona 85281.
J. inorg,nucl.Chem., 1970,Vol.32, pp. 1045to 1046. PergamonPress. Printedin Great Britain
Reaction of titanium (IV) chloride with oxalic and succinic acids* (Received 16 September 1969) INTRODUCTION THE REACTIONS of titanium (IV) halides with many classes of organic compounds to form complexes have been extensively studied. Reactions of titanium(IV) bromide with adipic and succinic acids results in products where two acid groups were present per molecule[l]. In previous work, we reported the preparation of titanium(IV) dichlorodiacetate and titanium(IV) dichloridipropionate and postulated a dimer formed by the coordination of the carbonyl oxygens of the acyl groups of one molecule to the titanium atom of an adjacent molecule resulting in titanium having a coordination number of six [2]. We report here the results obtained from the reaction of titanium(IV) chloride with oxalic and succinic acids. EXPERIMENTAL Chemicals. Purified grade titanium tetrachloride was used. The organic acids were reagent grade. The chloroform was dried over calcium hydride. Procedures. All procedures were carried out in a dry box under a nitrogen atmosphere. The dicarboxylic acid was accurately weighed into a 500 ml three-neck flask and stirred in a chloroform slurry. The titanium(I V) chloride dissolved in chloroform was added from an addition funnel after the reaction vessel was cooled to 0°. The mole ratio of titanium(IV) chloride to acid was 1 : 1. After 30 rain, the reaction mixture was slowly heated to the reflux temperature of chloroform and refluxed for 24 hr at which time the evolution of hydrogen chloride ceased. The solid yellow products were insoluble in chloroform. Although they were not recrystallized, they were washed with chloroform. Yields of 83 per cent TIC12C204 and 78 per cent TiCI2C4H404 were obtained. The titanium was analyzed for gravimetrically. Samples of the reaction product were hydrolyzed with 6 M NH4OH to form hydrated TiO2, NH4CI, and ammonium salts of the dicarboxylic acids. The samples were dried at 600° thus subliming or decomposing the ammonium salts. The presence of acyl and chloride groups necessitated a simultaneous determination for each. The samples were hydrolyzed with excess standard NaOH and backtitrated with standard HCI to a phenolphthalein end point. The infrared spectra were obtained using a Perkin-Elmer model 137-B spectrophotometer with *Some work done at North Dakota State University, Fargo, North Dakota. 1. S. Prasad and R. C. Srivastava, J. Indian chem. Soc. 39, 9 (1962). 2. D. Schwartz, C. Johnson, J. Ludwig and M. Morris, J. inorg, nucL Chem. 26, 2025 (1964).
1046
Notes
NaCI optics. The spectra of the acids and the dried titanium(IV) chloride complexes were obtained as nujol mulls. The nujol was dried over sodium. RESULTS AND DISCUSSION In Table 1, the analyses indicate that the resulting products contain one mole of acid which replaced two atoms of chlorine. Table 1. Analyses of the titanium(I V) chloride-dicarboxylic acid reaction products
Acid Oxalic Succinic
of product TiCIzC204 TiCIzC4H404
Calcd (%) Ti CI acyl 23.2 20.4
34.3 30.2
42.5 49.4
Found (%) Ti CI acyl 22.2 20.4
34.7 42.5 2 9 . 1 50.5
Moles of HCI evolved per acid used 2.03 2.08
Analyses of the i.r. spectra of the reaction products and the original acids show that the broad absorption band at 3000 cm -t assigned to the hydroxyl groups of the original acids has disappeared in the spectra of the titanium complexes. The free acids show the characteristic absorption at 1650-1700 cm -1. In the reaction product, this band is reduced. A weak band at 1580 cm -1 is present in the complex which is indicative of coordination between the carbonyl oxygen and a titanium atom. This shift in carbonyl frequency has been observed in other titanium acylates[2] and addition complexes with carbonyl compounds [3, 4, 5]. Titanium apparently exhibits a coordination number of six in the titanium oxalate and succinate compounds isolated in this work. A titanium-centered octahedral structure is likely, one in which two adjacent corners would be occupied by oxygen atoms, bridged via carbon atoms of the acyl group. Oxalate bridges are well-known in some complex ions [6]. Since molecular weight data could not be obtained, it is not known if the titanium oxalate and succinate compounds are monomeric or polymeric. Since both the monomer and polymer could involve five-membered rings, steric considerations would probably not be an important factor in the structure. 3. 4. 5. 6.
D. Schwartz and B. Larson, J. less common Metals 5,365 (1963). D. Schwartz and P. Bernd, J. less common Metals 7, 108 (1964). D. Schwartz and R. Heyer, J. inorg, nucl. Chem. 29, 1384 (1967). E. S. Gound, Inorganic Reactions and Structures, 2nd Edn. p. 329. Holt, New York (1962).
Department o f Chemistry Memphis State University Memphis, Tenn. 38111 U.S ~4 .
D. S C H W A R T Z P. R E S K l t
tPresent address: Moorhead State College, Moorhead, Minnesota.
J. inorg,nucl.Chem.,1970,Vol.32, pp. 1046to !048. PergamonPress. Printedin Great Britain
Hydrido, tetrakis(piperidine) complexes of iridium(Ill) (Received 25 September 1969) A NOVEL tetrakis(piperidine)-iridium(lll) complex which appeared to contain a coordinated hydride ion has been described in a recent communication [ 1] from these laboratories. Conclusive evidence for 1. E. R. Birnbaum,J. inorg, nucl. Chem. 31, 2628 (1969).
1{)45
A c k n o w l e d g e m e n t - S u p p o r t received for this investigation under contract DA-31-124-ARO(D)-35 is gratefully acknowledged. T. H. C H A N G * T H E R A D MOELLER¢
Noyes Chemical Laboratory University o f Illinois Urbana, Ill. 61801 U.S wt .
C H R I S T O P H E R W. ALLEN
Department o f Chemistry University o f Vermont Burlington, Vermont 05401 U.S.A.
* Present address: Department of Chemistry, National Taiwan University, Taipei, Taiwan. t Present address; Department of Chemistry, Arizona State University, Tempe, Arizona 85281.
J. inorg,nucl.Chem., 1970,Vol.32, pp. 1045to 1046. PergamonPress. Printedin Great Britain
Reaction of titanium (IV) chloride with oxalic and succinic acids* (Received 16 September 1969) INTRODUCTION THE REACTIONS of titanium (IV) halides with many classes of organic compounds to form complexes have been extensively studied. Reactions of titanium(IV) bromide with adipic and succinic acids results in products where two acid groups were present per molecule[l]. In previous work, we reported the preparation of titanium(IV) dichlorodiacetate and titanium(IV) dichloridipropionate and postulated a dimer formed by the coordination of the carbonyl oxygens of the acyl groups of one molecule to the titanium atom of an adjacent molecule resulting in titanium having a coordination number of six [2]. We report here the results obtained from the reaction of titanium(IV) chloride with oxalic and succinic acids. EXPERIMENTAL Chemicals. Purified grade titanium tetrachloride was used. The organic acids were reagent grade. The chloroform was dried over calcium hydride. Procedures. All procedures were carried out in a dry box under a nitrogen atmosphere. The dicarboxylic acid was accurately weighed into a 500 ml three-neck flask and stirred in a chloroform slurry. The titanium(I V) chloride dissolved in chloroform was added from an addition funnel after the reaction vessel was cooled to 0°. The mole ratio of titanium(IV) chloride to acid was 1 : 1. After 30 rain, the reaction mixture was slowly heated to the reflux temperature of chloroform and refluxed for 24 hr at which time the evolution of hydrogen chloride ceased. The solid yellow products were insoluble in chloroform. Although they were not recrystallized, they were washed with chloroform. Yields of 83 per cent TIC12C204 and 78 per cent TiCI2C4H404 were obtained. The titanium was analyzed for gravimetrically. Samples of the reaction product were hydrolyzed with 6 M NH4OH to form hydrated TiO2, NH4CI, and ammonium salts of the dicarboxylic acids. The samples were dried at 600° thus subliming or decomposing the ammonium salts. The presence of acyl and chloride groups necessitated a simultaneous determination for each. The samples were hydrolyzed with excess standard NaOH and backtitrated with standard HCI to a phenolphthalein end point. The infrared spectra were obtained using a Perkin-Elmer model 137-B spectrophotometer with *Some work done at North Dakota State University, Fargo, North Dakota. 1. S. Prasad and R. C. Srivastava, J. Indian chem. Soc. 39, 9 (1962). 2. D. Schwartz, C. Johnson, J. Ludwig and M. Morris, J. inorg, nucL Chem. 26, 2025 (1964).
1046
Notes
NaCI optics. The spectra of the acids and the dried titanium(IV) chloride complexes were obtained as nujol mulls. The nujol was dried over sodium. RESULTS AND DISCUSSION In Table 1, the analyses indicate that the resulting products contain one mole of acid which replaced two atoms of chlorine. Table 1. Analyses of the titanium(I V) chloride-dicarboxylic acid reaction products
Acid Oxalic Succinic
of product TiCIzC204 TiCIzC4H404
Calcd (%) Ti CI acyl 23.2 20.4
34.3 30.2
42.5 49.4
Found (%) Ti CI acyl 22.2 20.4
34.7 42.5 2 9 . 1 50.5
Moles of HCI evolved per acid used 2.03 2.08
Analyses of the i.r. spectra of the reaction products and the original acids show that the broad absorption band at 3000 cm -t assigned to the hydroxyl groups of the original acids has disappeared in the spectra of the titanium complexes. The free acids show the characteristic absorption at 1650-1700 cm -1. In the reaction product, this band is reduced. A weak band at 1580 cm -1 is present in the complex which is indicative of coordination between the carbonyl oxygen and a titanium atom. This shift in carbonyl frequency has been observed in other titanium acylates[2] and addition complexes with carbonyl compounds [3, 4, 5]. Titanium apparently exhibits a coordination number of six in the titanium oxalate and succinate compounds isolated in this work. A titanium-centered octahedral structure is likely, one in which two adjacent corners would be occupied by oxygen atoms, bridged via carbon atoms of the acyl group. Oxalate bridges are well-known in some complex ions [6]. Since molecular weight data could not be obtained, it is not known if the titanium oxalate and succinate compounds are monomeric or polymeric. Since both the monomer and polymer could involve five-membered rings, steric considerations would probably not be an important factor in the structure. 3. 4. 5. 6.
D. Schwartz and B. Larson, J. less common Metals 5,365 (1963). D. Schwartz and P. Bernd, J. less common Metals 7, 108 (1964). D. Schwartz and R. Heyer, J. inorg, nucl. Chem. 29, 1384 (1967). E. S. Gound, Inorganic Reactions and Structures, 2nd Edn. p. 329. Holt, New York (1962).
Department o f Chemistry Memphis State University Memphis, Tenn. 38111 U.S ~4 .
D. S C H W A R T Z P. R E S K l t
tPresent address: Moorhead State College, Moorhead, Minnesota.
J. inorg,nucl.Chem.,1970,Vol.32, pp. 1046to !048. PergamonPress. Printedin Great Britain
Hydrido, tetrakis(piperidine) complexes of iridium(Ill) (Received 25 September 1969) A NOVEL tetrakis(piperidine)-iridium(lll) complex which appeared to contain a coordinated hydride ion has been described in a recent communication [ 1] from these laboratories. Conclusive evidence for 1. E. R. Birnbaum,J. inorg, nucl. Chem. 31, 2628 (1969).