Vanadium(IV) Oxy(acetylacetonate)

VANADIUM(ZV) OXY(ACETYLACET0NATE) 113 35. J. F. STEINBACH and F. FREISER: Anal. Chem., 26, 881 (1953): 26,375 36. A. JOB and P. GOISSEDET: Compt. rend., 167, 50 (1913). 37. F. FEIGL and E. BACKER: ilionatsh., 49, 401 (1928). 38. G. Jantsch and E. hIEYER: Ber., 63B, 1577 (1920). 39. E. KUROWSKI: ibid., 43, 1078 (1910). 40. R. C. MENZIES: J. Chem. SOC., 1934, 1755. 41. G. T. MORGAN and R. A. S. CASTELL: ibid., 1928, 3252. 42. A. ROSENHEIM and A. BERTHEIM: 2. anorg. Chem., 34, 425 (1903). 43. G. URBAIN: Bull. soc. chim. Paris, 3 16, 347 (1896). 44. BRITISH DYESTUFF CORP., LTD., and S. COFFEY: British patent 289,493 (Oct. 28, 1926); cj. C. A., 23, 606 (1929). 45. N. V. SIDGWICK and F. hl. BREWER: J. Chem. SOC., 127, 2379 (1925). 46. A. COMBES: Compt. rend., 106, 868 (1887). 47. B. CIOCCA: Gazz. chim. ituZ., 67, 346 (1937). 48. F. GACK: Monatsh., 21, 98 (1900). 49. W. BILTZ and J. A. CLINCH: 2. anorg. Chem., 40, 218 (1904). 50. W. S. FYFE: Anal. Chem., 23, 174 (1951). 51. G. H. CARTLEDGE: U.S. patent 2,556,316 (June 12, 1951); cf. C. A., 46, 52. A. COMBES: Compt. rend., 119, 1221 (1894). 53. A. CONBES: ibid., 108, 405 (1889). 54. A. COMBES: Bull. soc. chim. France, 131 1, 345 (1889). 55. G. T. MORGAN and H. D. K. DREW: J. Chem. SOC., 119, 1058 (1921). 56. C. CHABRI and E. RENGADE: Compt. rend., 131, 1300 (1900); 132, 472 57. T. S. MOORE and M. W. YOUNG: J. Chem. SOC., 1932, 2694. 58. J. E. BLANCH: masters dissertation, The Pennsylvania State University, (1954). 1585 (1952). (1 901). 1956. 30. VANADIUM (IV) OXY (ACETYLACETONATE) pis (2,4-pentanediono) oxovanadium (IV) Vanadium(1V) oxy(acety1acetonate) has been prepared by direct reaction of acetylacetone (2,4-pentanedione) with either hydrous vanadium(1V) oxide or an aqueous solution of an oxovanadium(1V) Procedure A is an adaptation of this approach. The facts that acetyl- acetone can reduce vanadium(V) oxide to vanadium(1V) oxide, react as an acid4g5 with the latter to give the desired product, and behave as a solvent for that product are combined in procedure B to give a synthesis based directly upon readily available starting materials. Inorganic Syntheses, Volume V Edited by Therald Moeller Copyright 1957 by McGraw-Hill Book Company, Inc.114 INORGANIC SYNTHESES Procedure A Preparation from Vanadium(V) Oxide through Prior Reduction to Oxovanadium(1V) Ion VzOs + 2HzSO4 + CzHsOH 4 2VOSO4 + 3Hz0 + CHiCHO voso4 + 2C5HsOZ + Na2C034 VO(CsH70z)z + Na2S04 + HzO + COz SUBMITTED BY RICHARD A. ROWE* AND MARK M. JONES* CHECKED BY PETER BLocxt To 20 g. of pure vanadium(V) oxide (0.11 mol) in a 1-1. beaker are added 50 ml. of distilled water, 35 ml. of 96% (by weight) sulfuric acid, and 100 ml. of ethanol. The mixture is heated to boiling on a hot plate or steam bath and stirred. As the reaction proceeds, the initial slurry of vanadium(V) oxide darkens, becomes light green, and finally turns dark blue. The solution of vanadium(V) oxide and its reduction to vanadium(1V) are complete in 30 minutes. The solution is filtered and the filtrate returned to the 1-1. beaker. Then 50 ml. of freshly dis- tilled acetylacetone (ca. 0.49 mol) is added, and the solution is neutralized by ad ng a solution of 80 g. of anhydrous The sodium carbonate solution is added slowly with con- tinuous stirring to avoid excessive frothing.$ The pre- cipitated product is removed by filtration on a Buchner funnel and dried by drawing air through the filter cake. The yield of crude vanadium(1V) oxy(acety1acetonate) is 48 to 53 g. 75 to 83%, based upon vanadium(V) oxide used. The product is recrystallized from chloroform. sodium carbonate d P solved in 500 ml. of distilled water. * University of Illinois, Urbana, Ill. t The Pennsylvania State University, University Park, Pa. # The reaction is conveniently followed with a pH meter, precipitation At the end point, beginning at pH 3.5 and being complete at pH 5.5. addition of more sodium carbonate solution causes no more frothing. VANADZUM(ZV) OXY(ACETYLACET0NATE) 115 Anal. Calcd. for VO(C5H70z)2: C, 45.28; H, 5.28; V, 19.25. Found: C, 45.1; H, 5.37; V, 19.2.* Procedure B Direct Preparation from Vanadium(V) Oxide 2Vz05 + 9CsHsOz 4 4VO(CsH70z)z + (CH&O)&O + 5Hz0 SUBMITTED BY BURL E. RRYANTt AND w. CONARD FERNELIUSt CHECKED BY DARYLE H. BUSCH, R. CARL STOUFER, AND WILMER STRATTON 1 Five grams of technical vanadium(V) oxide (ca. 0.03 mol) is placed in a 200-ml. round-bottomed flask which is attached to a reflus condenser through a ground-glass joint. One hundred milliliters of commercial acetylacetone (ca. 0.98 mol)j/ is added, and the mixture is reflused gently for 24 hours. The suspension is filtered while hot,l/ and the filtrate is cooled. About 5 g. of product separates as tiny blue crystals. The remaining acetylacetone is removed by evaporation in a stream of air. The solid product is washed with acetone and ethyl ether and dried at 110. The yield is 10 g. (68%). Anal. Calcd. for VO(C5H,02)z: C, 45.28; H, 5.28; V, 19.25. Found: C, 45.09;* H, 5.33;* * Vanadium is determined by destroying the organic material with sulfuric t The Pennsylvania State University, University Park, Pa. $ The Ohio State University, Columbus, Ohio. Q The reaction apparently proceeds without difficulty with any quantity of vanadium(V) oxide if the specified ratio of reactants is maintained. Larger ratios of vanadium(V) oxide give large crystals or crystal aggregates of product in the reaction flask because the solubility of the product is exceeded. Vanadium (V) oxide prepared by decomposition of pure ammo- nium metavanadate at 250 gives higher yields of product but no increase in its purity. acid and igniting to vanadium(V) oxide.0 11 If the material is colored, it should be distilled before being used. 7 Resinous material may form and clog the filter. The addition of a small quantity of acetone before filtration alleviates this difficulty. The nature of the organic oxidation product is indefinite and is represented in an ideal- ized fashion in the equation as (CH&O)&O. * Data supplied by the checkers. 116 INORGANIC SYNTHESES V, 19.32. iMateria1 of analytical-reagent purity is obtained by recrystallization from acetone or acetylacetone, with a recovery of 50 to 80%. Properties Vanadium(1V) oxy(acety1acetonate) is a blue to blue- green compound, crystallizing in the monoclinic system with refractive indexes of a, 1.520; p, 1.676; y, 1.739. The compound was originally believed to be a 1-hydrate but is now known to be anhydrous. It forms addition compounds with pyridine, methylamine, and other amines.8 Vanadium(