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Derivatives of titanium with compounds having bidentate ligands
481
JOURNAL OF TME LESS-COMMON METALS
DERIVATIVES
OF TITANIUM BIDENTATE
IV. CHLORIDE
COMPOUNDS
K. C. I’XNI)E
OF TITANIUM
AND R. (‘. MEHROTRI\**
of Chemistvy,C~>ziuersity of Govakhpw, (Received
HAVING
LIGANDS
ACETYLACETONATES
U. 1LZ.PURl*, lI$t.
WITH
Govlakhpul,(Ilzdia)
January 29th. 1902)
The preparation of titanium dichloride diacetylacetone (TiClz(acac),) from titanium tetrachloride and titanium dichloride dialkoxide is described. It has been shown that the compound can be obtained by the reaction between titanium dialkoxidc diacetylacetone and hydrogen chloride, whereas it is converted into the alkoxide derivative by the reaction with alcohol in presence of anhydrous ammonia. These reactions together with low conductivities in nitrobcnzene confirm the simple monomeric formulation TiClz(acac)2. The preparation of titanium trichloride monoacetylacetone has been described and its reactions and those of the dichloride derivative, with alcohols and acids have been studied.
ROSENHEIM and coworkers1 first showed that the reaction between titanium tetrachloride and acetylacetone yielded deep red prisms of the compound, TiCls(acac). E&O. DILTHEY~ proved that the above reaction product had the empirical formula,
TiCla(acac)z. He further demonstrated that the compound crystallised from acetic acid and formed a compound with ferric chloride of the composition [Ti(acac)a1FeCla. In order to explain the formation of the above mixed derivative, he assumed that the initial titanium product was trimeric and could be assigned the structure, [Ti(acac)s]zTiCls. for this reaction:
The following would be the course which would require to be assumed TIC14 + 3H(acac) + rTiCl(acac)a
2 TiC14 +
TiCl(acac):j
-
3H(‘l
jTi(acac)sl2TiCl6
(r) (2)
(I) [Ti(acac)s]zTiCls
+ rFeCl3 +
~[Ti(acac)~,Fe(‘l~ (11)
+ TiCIt
(3)
In a number of detailed investigations3p7 conducted at these laboratories, it has been shown that the direct reaction of titanium tetrachloride with hydroxylic as well as carboxylic compounds, yields in every case only the dichloride derivative. However, in the above reaction (I), the formation of a monochloride derivative has been assumed. Further, the anion [TiCle]z- should have given by secondary dissociation, some titanium tetrachloride, which would have reacted with the excess of acetylace* l’resent address: I>ept. of Chemistry, The University, Kurukshctra, India. ** I’rescnt address: Ikpt. of Chemistry, Rajasthan Univrrsity, Jaipur, India
482
D. M. PURI,
K. C. PANDE,
R. C. MEHROTRA
tone or acetic acid solvent. In view of the above, a detailed study of the above reactions was undertaken. From the observed molecular weights in boiling benzene, acetone, carbon disulphide and chloroform, (I) has been shown to be monomeric*. Although very improbable, the observed monomeric molecular weight of compound with structure (I) could only be explained on the basis of complete ionisation in all the solvents as: [Ti(acac)a]zTiClG -+ z[Ti(acac)s]+ + [TiCls]2In order to check this point, the conductivities of (I) in nitrobenzene were measured and the low observed values (Table I) confirm the absence of appreciable dissociation. TABLE
I
I.180 1.476
6.866 6.766
1.771 2.066 2.952
7.046 8.567 7.916
This also, therefore, points to the monomeric formulation, Ti(acac)&lz. As shown below, the formulation is further supported by chemical evidence. Titanium dichloride diacetylacetone (I) did not appear to undergo any change on being refluxed with ethanol or isopropanol, but crystallised out on cooling with a molecule of alcohol of addition, TiCl~(acac)z..ROH. However, if the above reaction was carried out in the presence of ammonia, titanium dialkoxy diacetylacetone was formed TiCla(acac)g
-t 2ROH
2NH3-+
+
Ti(OR)s(acac)z
+
zNHCI
(4)
Similarly, compound (I) could be synthesised from dialkoxy titanium diacetylacetone by reacting with anhydrous hydrogen chloride in benzene9 Ti(OR)z(acac)z
+
zHCl-+
TiClg(acac):,
+
2ROH
(5)
Another route by which the same compound (I) can be obtained in a quantitative yield, is the reaction between titanium dialkoxy dichloride and acetylacetone: TiClZ(OEt)z
+
2H(acac)
+
TiClz(acac)~
+
2EtOH
(6)
In view of the monomeric nature of dialkoxy diacetylacetonelo and dialkoxy titanium dichloride derivative, the above simple quantitative reactions would be difficult to understand if a trimeric formula were assumed for the compound (I). By the reaction between titanium tetrachloride and acetylacetone (I : I molar ratio) in refluxing benzene, titanium trichloride monoacetylacetone can be crystallised in the form of dark red plates. This compound was found to react exothermally with ethanol with the replacement of only one chlorine atom by the ethanol group. TiCls(acac)
+
zEt0I-I
+
TiCl~(acac)(OEt).EtOH
+
WC1
(7)
A similar exothermic reaction occurs with acetic acid. However, on long refluxing in acetic acid, an equimolar mixture of titanyl diacetate and basic titanium triacetate is the final end product. As a result of a detailed study of the corresponding reaction between titanium tetrachloride and acetic acid 6~7, the above reaction can be assumed to proceed as follows J. ~ess-Co~l?~o~
.WefnZs, 4 (1962) 48x-486
CHLORIDE ACETYLACETONATES OF TITANIUJI TiCls(acac)
+ H(0Ac)
-----+ exothermic
C12Ti(acac) (O.&z) + HCl
ClzTi(O.\c)2
~‘l~Ti(OAc)~ + H(C1.J.c) -p--m--+ on refluxing (‘12Ti(OXc)2
The above
suggested
diacetylacetone
mechanism
is confirmed
on long refluxing,
finally yielding
I
H(acac)
(9)
ClTi(O,\c):< 7. HCL
+ ClTi(OXc):1 + O[Ti(O.-\c)sja I slow
can be recrystallised
(8)
and fast
+ H(OAc) ----d on rcfluxing
ClZTi(acac) (0ac)
483
rHC1
by the fact that
from acetic
(11)
titanium
acid unchanged;
the same products
dichloride
it is decomposed
as shown above.
.44p#aratus Apparatus used was similar to that described previouslyR. For calorimetric estimations, a BAUSCH AND LOMB calorimeter was used. Conductometric measurements were made on a PHILIPS magic fixed parallel
eye conductivity
plate cell was used for conductivity
apparatus.
A KOHLRAUSCH-type
measurements.
Material Titanium isopropanol, Acetic
tetrachloride acetylacetone,
(E. MERCK) was used and was distilled before use. Ethanol, and benzene were purified and dried in the usual manner*.
acid was dried by refluxing
redistilled ducts.
before
ilnalytical
methods
Titanium
use (b.p.2ro”).
and chlorine
with titanium
Titanium
were estimated
tetrachloridell.
alkoxides
Nitrobenzene
was
were PETER AND SPENCE pro-
gravimetrically.
Acetic
acid was estimated
by direct titration against a standard alkali solution. Acetylacetone calorimetrically with ferric alum according to the method described
was determined by BONNER AP\‘L)
THORUF~~. I . REACTIONS
Reaction between titanium tetrachloride and acetylacetone in excess in benzene Acetylacetone
(13.8 g) was added to a solution
of titanium
tetrachloride
(6.3 g) in
benzene (60 ml). The reaction mixture became hot and hydrogen chloride gas was evolved in dense fumes. It was refluxed (bath temperature 110’) until the evolution of hydrogen chloride gas ceased (z+ h). On cooling, a red crystalline mass was obtained which was dried under reduced pressure at 50~. Found: Ti, 15.3; Cl, 21.7; acac, 59.50,;,. Calcd. for TiClz(acac)z: Ti, 15.1; Cl, 22.4; acac, 62.5%. Reaction between titanium dichloride diacetylacetone and ethanol Ethanol (16.32 g) was added to titanium dichloride diacetylacetone (I.35 g). The compound dissolved without evolution of any noticeable heat. It was refluxed
484
D. hf.PURT, K.C. PAhTDE,R.C. MEHROTRA
for five hours (bath temperature ~oo~--~~o~)but no evolution of hydrogen chloride was observed. The excess of alcohol was removed under reduced pressure at 50°C. A yellow viscous liquid was obtained which on keeping overnight solidified to needleshaped yellow crystals (1.53 g). Found: Ti, 13.73;Cl, 19.52%. Calcd. for TiClz(acac)z. EtOH: Ti, 13.22;Cl, 19.550/o. Reaction between titan&n
~~~~l~~~de diacetylacetone
and iso$vopanol
Isopropanol (8.86 g) was added to titanium dichloride diacetylacetone (1.98 g). The compound dissolved in alcohol without liberation of heat. On refluxing for two hours at rzo“, no hydrogen chloride gas was evolved. An orange crystalline solid (2.31 g) was obtained after drying under reduced pressure at 50°C. Found: Ti, 1260; Cl, r8.8g%. Calcd. for TiClz(acac)z.PrgOH: Ti, 12.74; Cl, 18.84%.
Titanium dichloride diacetylacetone (2.0 g) was dissolved in benzene (30 ml) and to this was added ethanol (IO g). Dry ammonia was passed into the reaction mixture when it became hot and a white insoluble mass precipitated out. It was filtered off after cooling and the solvent was removed. A viscous orange liquid was obtained which crystallised to a light yellow solid (2.6 g). Found: Ti, 14.58; acac, 60.00/. Calcd. for Ti(O~t)~(acac)~: Ti, 14.2; acac, $?~9~/~. Reaction between titalzium dichloride ammonia
diacetylacetone
and iso$ropanol
in the presence of
Isopropanol (4.7 g) was added to titanium dichloride diacetylacetone (6.0 g) in benzene (40 ml). Ammonia was passed till no more heat was evolved. The white insoluble precipitate was filtered off; solvent was removed from the filtrate and the product was dried under reduced pressure as usual. An orange-coloured liquid was obtained (4.0 g). Found: Ti, 14.40/b. A portion of the above product (2.8 g) was purified by distillation (123”/0.5 mm). Found: Ti, 13.3; acac, 55.30/b. Calcd. for Ti(OPri)z(acac)z: Ti, 13.1; acac, 54.4%. Reaction between &a&urn diethoxide
dichloride
and acetylacetone
in benzene
Acetylacetone (3 g) was added to titanium diethoxide dichloride (1.8 g), prepared as described by ~ARDLAW et al. 13, in benzene (15 ml) and the reaction mixture was refluxed at a bath temperature of IIO’ for one hour. On concentrating the mixture, a red crystalline mass was deposited which was dried under reduced pressure. Found : Ti, 15.3; Cl, 21.6; acac, 60.3%. Calcd. for TiClz(acac)s: Ti, I~,I;Cl, 22.4; acac, 62.5%. Reaction between titanium diethoxide
diacetylacetone
and hydrogen chloride
An excess of hydrogen chloride gas was passed into titanium diethoxide diacetylacetone (3.2 g) dissolved in benzene (20 ml). Heat was evolved and the reactionmixture gradually changed its colour from yellow to orange. On concentrating the reaction mixture, red cqrstals were obtained. These were separated and dried under reduced pressure. Found: Ti, 15.3; Cl, 21.7; acac, 63.1%. Calcd. for TiClz(acac)z: Ti, 15.1; Cl, 22.4; acac, 62.5%. J. Less-Common
Metals,
4 (1962)
481-480
CHLORIDE ACET~‘LA(‘ETONATES
Reaction
between
titanium
tetrachloride
485
OF TITANIUM
and acetylacetone
in the molar
ratio of I : I in
benzene Acetplacetone
(7.5 g) was added to titanium
tetrachloride
(14.5 g) in benzene
(50
ml). Hydrogen chloride gas was evolved as dense fumes. The mixture became hot and red in colour. The reaction mixture was refluxed for four hours till all hydrogen chloride gas was removed. On cooling, dark red shining crystals were obtained, which where dried under reduced pressure (7.7 g). Found: Ti, 19.03; (:alcd. for TiCL(acac) : Ti, 18.93; Cl, 42.0; acac, 39.12~;. Reaction
between titanium
trichloride
monoacetylaceto?ze
Cl, 41.95;
and ethanol
acac, 40.30;,.
in excess
Ethanol (25 ml) was added to titanium trichloride monoacetylacetone (3.7 g). The compound, on shaking, dissolved immediately, with evolution of heat. The reaction mixture On cooling,
was refluxed for two hours till all hydrogen chloride gas was removed.
an orange-red
solution
was obtained.‘Excess
alcohol
was removed
by
distillation and the last traces were removed under reduced pressure at 50”. .4n orangered viscous liquid was obtained. Found: Ti, 15.37; Cl, 23.07”,{,. Calcd. for TiClz(acac) (OEt).EtOH: Reaction
Ti,r5.5;
between
Cl,23.0;/;.
titanium
trichloride
monoacetylacetone
and
acetic
acid
under
mild
refluxing hcetic acid (IO ml) was added to titanium trichloride monoacetylacetonc (0.95 g). The compound dissolved on shaking but again some orange-coloured precipitate settled. The mixture became slightly warm and the colour changed from red to orange. The mixture was refluxed at controlled bath temperature of 120” till all hydrogen chloride gas was removed (I h). On cooling and keeping overnight, light orange crystals $~“C. Found: Reaction refluxing
(0.87 g) were obtained,
Ti, 17.17;
betideen
Cl,24.87%.
titanium
which were dried under reduced
Calcd. for TiClp(acac)(OAc)
trichloride
monoacetylacetone
pressure
at
: Ti, 17.33; Cl, 25.64’0.
and acetic
acid
ox continued
Acetic acid (20 ml) was added to titanium trichloride monoacetylacetone (0.67 g). r\fter refluxing for two hours at 160’ bath temperature, a yellowish white solid separated.
The refluxing
(6 h). After decanting
was continued
the supernatant
till all the hydrogen
chloride gas was removed
liquid, the white solid (0.67 g) left, was dried
under reduced pressure at room temperature. Found: Ti, 21.97; 0,4c, 71.3!&. Calcd. for equimolar mixture of Ti O(OAc)t and O[Ti(OAc)3]2: Ti, zz.z; OAc, 72.83(1/o. Reaction ing
between titanium
dichloride
diaretylacetone
a&
acetic acid on continlted reflclx-
Acetic acid (20 ml) was added to titanium dichloride diacetylacetone (0.95 g). The compound dissolved in the acid on refluxing. After refluxing for two hours, the compound decomposed and a yellowish white solid separated. After eight hours, the evolution of hydrogen chloride gas ceased. The mixture was cooled, the supernatant liquid decanted, and the compound dried under reduced pressure at room temperature. A yellowish white solid (0.47 g) was obtained. Found: Ti, 22.02; OAc, 72.14:~. Calcd. for equimolar mixture of TiO(OAc)s and O/:Ti(0,4c)&: Ti, 22.2; OAc, 72.83%.
486
D. M. PURI,
K. C. PANDE,
R. C. MEHROTRA
ACKNOWLEDGEMENTS
One of us (D.M.P.) is grateful to the Scientific Research Committee, U.P., for a Research Assistantship, during the tenure of which this work was carried out. REFERENCES 1 A. ROSENHEIM, W. LOEWENSTAMM AND L. SINGER, Ber. de&. them. Ges., 36 (1903) 1833. a W. DILTHEY, Ber. de&. them. Ges., 37 (1904) 588. 3 I. D. VARMA AND R. C. MEHROTRA, 1. pmkt. Chem., 8 (1959) 64. 4 I. D. VARFAA AND R. C. MMEHROTRA,J. pvakt. Chem., 8 (1959) 235. 5 I. D. VARMA .%ND R. C. MEHROTRA, J. Less-Common Metals, 3 (1961) 321. 6 K. C. PANDE AND R. C. MEHROTKA, J. prakt. Chem., 5 (1957) IOI. 7 R. N. KAPOOR, K. C. PANDE AND R. C. MEHROTRA, J. Indian. Chem. SW., 35 (1958) 151. 8 D. M. PURI AND R. C. MEHROTKA, J. Less-Comlnon Metals, 3 (1961) 247. 9 R. C. MEHROTRA, J. Indian. Chew. Soc., 30 (1953) 731. 10 A. YAMAMOTO AND S. KAMBARA, J. Am. Chem. Sot., 79 (1957) 4344. XI. R. C. YOUNG, Inorg. Syntheses, 20 (1946) 119. 1% T. G. BONNER AND M. P. THORNE, Amzlyst, 7g (1954) 759. *a J. S. JENNINGS, W. WARDLAW AND W. J. R. WAY, J, Chwn. SW., (1936) 637. D. C. BRADLEY, D. C. HANCOCK AND W. WARDLAW, J. Chem. Sot., (1g.p) 2773.
J. Less-Common
Metals, 4 (1962) 481-486
JOURNAL OF TME LESS-COMMON METALS
DERIVATIVES
OF TITANIUM BIDENTATE
IV. CHLORIDE
COMPOUNDS
K. C. I’XNI)E
OF TITANIUM
AND R. (‘. MEHROTRI\**
of Chemistvy,C~>ziuersity of Govakhpw, (Received
HAVING
LIGANDS
ACETYLACETONATES
U. 1LZ.PURl*, lI$t.
WITH
Govlakhpul,(Ilzdia)
January 29th. 1902)
The preparation of titanium dichloride diacetylacetone (TiClz(acac),) from titanium tetrachloride and titanium dichloride dialkoxide is described. It has been shown that the compound can be obtained by the reaction between titanium dialkoxidc diacetylacetone and hydrogen chloride, whereas it is converted into the alkoxide derivative by the reaction with alcohol in presence of anhydrous ammonia. These reactions together with low conductivities in nitrobcnzene confirm the simple monomeric formulation TiClz(acac)2. The preparation of titanium trichloride monoacetylacetone has been described and its reactions and those of the dichloride derivative, with alcohols and acids have been studied.
ROSENHEIM and coworkers1 first showed that the reaction between titanium tetrachloride and acetylacetone yielded deep red prisms of the compound, TiCls(acac). E&O. DILTHEY~ proved that the above reaction product had the empirical formula,
TiCla(acac)z. He further demonstrated that the compound crystallised from acetic acid and formed a compound with ferric chloride of the composition [Ti(acac)a1FeCla. In order to explain the formation of the above mixed derivative, he assumed that the initial titanium product was trimeric and could be assigned the structure, [Ti(acac)s]zTiCls. for this reaction:
The following would be the course which would require to be assumed TIC14 + 3H(acac) + rTiCl(acac)a
2 TiC14 +
TiCl(acac):j
-
3H(‘l
jTi(acac)sl2TiCl6
(r) (2)
(I) [Ti(acac)s]zTiCls
+ rFeCl3 +
~[Ti(acac)~,Fe(‘l~ (11)
+ TiCIt
(3)
In a number of detailed investigations3p7 conducted at these laboratories, it has been shown that the direct reaction of titanium tetrachloride with hydroxylic as well as carboxylic compounds, yields in every case only the dichloride derivative. However, in the above reaction (I), the formation of a monochloride derivative has been assumed. Further, the anion [TiCle]z- should have given by secondary dissociation, some titanium tetrachloride, which would have reacted with the excess of acetylace* l’resent address: I>ept. of Chemistry, The University, Kurukshctra, India. ** I’rescnt address: Ikpt. of Chemistry, Rajasthan Univrrsity, Jaipur, India
482
D. M. PURI,
K. C. PANDE,
R. C. MEHROTRA
tone or acetic acid solvent. In view of the above, a detailed study of the above reactions was undertaken. From the observed molecular weights in boiling benzene, acetone, carbon disulphide and chloroform, (I) has been shown to be monomeric*. Although very improbable, the observed monomeric molecular weight of compound with structure (I) could only be explained on the basis of complete ionisation in all the solvents as: [Ti(acac)a]zTiClG -+ z[Ti(acac)s]+ + [TiCls]2In order to check this point, the conductivities of (I) in nitrobenzene were measured and the low observed values (Table I) confirm the absence of appreciable dissociation. TABLE
I
I.180 1.476
6.866 6.766
1.771 2.066 2.952
7.046 8.567 7.916
This also, therefore, points to the monomeric formulation, Ti(acac)&lz. As shown below, the formulation is further supported by chemical evidence. Titanium dichloride diacetylacetone (I) did not appear to undergo any change on being refluxed with ethanol or isopropanol, but crystallised out on cooling with a molecule of alcohol of addition, TiCl~(acac)z..ROH. However, if the above reaction was carried out in the presence of ammonia, titanium dialkoxy diacetylacetone was formed TiCla(acac)g
-t 2ROH
2NH3-+
+
Ti(OR)s(acac)z
+
zNHCI
(4)
Similarly, compound (I) could be synthesised from dialkoxy titanium diacetylacetone by reacting with anhydrous hydrogen chloride in benzene9 Ti(OR)z(acac)z
+
zHCl-+
TiClg(acac):,
+
2ROH
(5)
Another route by which the same compound (I) can be obtained in a quantitative yield, is the reaction between titanium dialkoxy dichloride and acetylacetone: TiClZ(OEt)z
+
2H(acac)
+
TiClz(acac)~
+
2EtOH
(6)
In view of the monomeric nature of dialkoxy diacetylacetonelo and dialkoxy titanium dichloride derivative, the above simple quantitative reactions would be difficult to understand if a trimeric formula were assumed for the compound (I). By the reaction between titanium tetrachloride and acetylacetone (I : I molar ratio) in refluxing benzene, titanium trichloride monoacetylacetone can be crystallised in the form of dark red plates. This compound was found to react exothermally with ethanol with the replacement of only one chlorine atom by the ethanol group. TiCls(acac)
+
zEt0I-I
+
TiCl~(acac)(OEt).EtOH
+
WC1
(7)
A similar exothermic reaction occurs with acetic acid. However, on long refluxing in acetic acid, an equimolar mixture of titanyl diacetate and basic titanium triacetate is the final end product. As a result of a detailed study of the corresponding reaction between titanium tetrachloride and acetic acid 6~7, the above reaction can be assumed to proceed as follows J. ~ess-Co~l?~o~
.WefnZs, 4 (1962) 48x-486
CHLORIDE ACETYLACETONATES OF TITANIUJI TiCls(acac)
+ H(0Ac)
-----+ exothermic
C12Ti(acac) (O.&z) + HCl
ClzTi(O.\c)2
~‘l~Ti(OAc)~ + H(C1.J.c) -p--m--+ on refluxing (‘12Ti(OXc)2
The above
suggested
diacetylacetone
mechanism
is confirmed
on long refluxing,
finally yielding
I
H(acac)
(9)
ClTi(O,\c):< 7. HCL
+ ClTi(OXc):1 + O[Ti(O.-\c)sja I slow
can be recrystallised
(8)
and fast
+ H(OAc) ----d on rcfluxing
ClZTi(acac) (0ac)
483
rHC1
by the fact that
from acetic
(11)
titanium
acid unchanged;
the same products
dichloride
it is decomposed
as shown above.
.44p#aratus Apparatus used was similar to that described previouslyR. For calorimetric estimations, a BAUSCH AND LOMB calorimeter was used. Conductometric measurements were made on a PHILIPS magic fixed parallel
eye conductivity
plate cell was used for conductivity
apparatus.
A KOHLRAUSCH-type
measurements.
Material Titanium isopropanol, Acetic
tetrachloride acetylacetone,
(E. MERCK) was used and was distilled before use. Ethanol, and benzene were purified and dried in the usual manner*.
acid was dried by refluxing
redistilled ducts.
before
ilnalytical
methods
Titanium
use (b.p.2ro”).
and chlorine
with titanium
Titanium
were estimated
tetrachloridell.
alkoxides
Nitrobenzene
was
were PETER AND SPENCE pro-
gravimetrically.
Acetic
acid was estimated
by direct titration against a standard alkali solution. Acetylacetone calorimetrically with ferric alum according to the method described
was determined by BONNER AP\‘L)
THORUF~~. I . REACTIONS
Reaction between titanium tetrachloride and acetylacetone in excess in benzene Acetylacetone
(13.8 g) was added to a solution
of titanium
tetrachloride
(6.3 g) in
benzene (60 ml). The reaction mixture became hot and hydrogen chloride gas was evolved in dense fumes. It was refluxed (bath temperature 110’) until the evolution of hydrogen chloride gas ceased (z+ h). On cooling, a red crystalline mass was obtained which was dried under reduced pressure at 50~. Found: Ti, 15.3; Cl, 21.7; acac, 59.50,;,. Calcd. for TiClz(acac)z: Ti, 15.1; Cl, 22.4; acac, 62.5%. Reaction between titanium dichloride diacetylacetone and ethanol Ethanol (16.32 g) was added to titanium dichloride diacetylacetone (I.35 g). The compound dissolved without evolution of any noticeable heat. It was refluxed
484
D. hf.PURT, K.C. PAhTDE,R.C. MEHROTRA
for five hours (bath temperature ~oo~--~~o~)but no evolution of hydrogen chloride was observed. The excess of alcohol was removed under reduced pressure at 50°C. A yellow viscous liquid was obtained which on keeping overnight solidified to needleshaped yellow crystals (1.53 g). Found: Ti, 13.73;Cl, 19.52%. Calcd. for TiClz(acac)z. EtOH: Ti, 13.22;Cl, 19.550/o. Reaction between titan&n
~~~~l~~~de diacetylacetone
and iso$vopanol
Isopropanol (8.86 g) was added to titanium dichloride diacetylacetone (1.98 g). The compound dissolved in alcohol without liberation of heat. On refluxing for two hours at rzo“, no hydrogen chloride gas was evolved. An orange crystalline solid (2.31 g) was obtained after drying under reduced pressure at 50°C. Found: Ti, 1260; Cl, r8.8g%. Calcd. for TiClz(acac)z.PrgOH: Ti, 12.74; Cl, 18.84%.
Titanium dichloride diacetylacetone (2.0 g) was dissolved in benzene (30 ml) and to this was added ethanol (IO g). Dry ammonia was passed into the reaction mixture when it became hot and a white insoluble mass precipitated out. It was filtered off after cooling and the solvent was removed. A viscous orange liquid was obtained which crystallised to a light yellow solid (2.6 g). Found: Ti, 14.58; acac, 60.00/. Calcd. for Ti(O~t)~(acac)~: Ti, 14.2; acac, $?~9~/~. Reaction between titalzium dichloride ammonia
diacetylacetone
and iso$ropanol
in the presence of
Isopropanol (4.7 g) was added to titanium dichloride diacetylacetone (6.0 g) in benzene (40 ml). Ammonia was passed till no more heat was evolved. The white insoluble precipitate was filtered off; solvent was removed from the filtrate and the product was dried under reduced pressure as usual. An orange-coloured liquid was obtained (4.0 g). Found: Ti, 14.40/b. A portion of the above product (2.8 g) was purified by distillation (123”/0.5 mm). Found: Ti, 13.3; acac, 55.30/b. Calcd. for Ti(OPri)z(acac)z: Ti, 13.1; acac, 54.4%. Reaction between &a&urn diethoxide
dichloride
and acetylacetone
in benzene
Acetylacetone (3 g) was added to titanium diethoxide dichloride (1.8 g), prepared as described by ~ARDLAW et al. 13, in benzene (15 ml) and the reaction mixture was refluxed at a bath temperature of IIO’ for one hour. On concentrating the mixture, a red crystalline mass was deposited which was dried under reduced pressure. Found : Ti, 15.3; Cl, 21.6; acac, 60.3%. Calcd. for TiClz(acac)s: Ti, I~,I;Cl, 22.4; acac, 62.5%. Reaction between titanium diethoxide
diacetylacetone
and hydrogen chloride
An excess of hydrogen chloride gas was passed into titanium diethoxide diacetylacetone (3.2 g) dissolved in benzene (20 ml). Heat was evolved and the reactionmixture gradually changed its colour from yellow to orange. On concentrating the reaction mixture, red cqrstals were obtained. These were separated and dried under reduced pressure. Found: Ti, 15.3; Cl, 21.7; acac, 63.1%. Calcd. for TiClz(acac)z: Ti, 15.1; Cl, 22.4; acac, 62.5%. J. Less-Common
Metals,
4 (1962)
481-480
CHLORIDE ACET~‘LA(‘ETONATES
Reaction
between
titanium
tetrachloride
485
OF TITANIUM
and acetylacetone
in the molar
ratio of I : I in
benzene Acetplacetone
(7.5 g) was added to titanium
tetrachloride
(14.5 g) in benzene
(50
ml). Hydrogen chloride gas was evolved as dense fumes. The mixture became hot and red in colour. The reaction mixture was refluxed for four hours till all hydrogen chloride gas was removed. On cooling, dark red shining crystals were obtained, which where dried under reduced pressure (7.7 g). Found: Ti, 19.03; (:alcd. for TiCL(acac) : Ti, 18.93; Cl, 42.0; acac, 39.12~;. Reaction
between titanium
trichloride
monoacetylaceto?ze
Cl, 41.95;
and ethanol
acac, 40.30;,.
in excess
Ethanol (25 ml) was added to titanium trichloride monoacetylacetone (3.7 g). The compound, on shaking, dissolved immediately, with evolution of heat. The reaction mixture On cooling,
was refluxed for two hours till all hydrogen chloride gas was removed.
an orange-red
solution
was obtained.‘Excess
alcohol
was removed
by
distillation and the last traces were removed under reduced pressure at 50”. .4n orangered viscous liquid was obtained. Found: Ti, 15.37; Cl, 23.07”,{,. Calcd. for TiClz(acac) (OEt).EtOH: Reaction
Ti,r5.5;
between
Cl,23.0;/;.
titanium
trichloride
monoacetylacetone
and
acetic
acid
under
mild
refluxing hcetic acid (IO ml) was added to titanium trichloride monoacetylacetonc (0.95 g). The compound dissolved on shaking but again some orange-coloured precipitate settled. The mixture became slightly warm and the colour changed from red to orange. The mixture was refluxed at controlled bath temperature of 120” till all hydrogen chloride gas was removed (I h). On cooling and keeping overnight, light orange crystals $~“C. Found: Reaction refluxing
(0.87 g) were obtained,
Ti, 17.17;
betideen
Cl,24.87%.
titanium
which were dried under reduced
Calcd. for TiClp(acac)(OAc)
trichloride
monoacetylacetone
pressure
at
: Ti, 17.33; Cl, 25.64’0.
and acetic
acid
ox continued
Acetic acid (20 ml) was added to titanium trichloride monoacetylacetone (0.67 g). r\fter refluxing for two hours at 160’ bath temperature, a yellowish white solid separated.
The refluxing
(6 h). After decanting
was continued
the supernatant
till all the hydrogen
chloride gas was removed
liquid, the white solid (0.67 g) left, was dried
under reduced pressure at room temperature. Found: Ti, 21.97; 0,4c, 71.3!&. Calcd. for equimolar mixture of Ti O(OAc)t and O[Ti(OAc)3]2: Ti, zz.z; OAc, 72.83(1/o. Reaction ing
between titanium
dichloride
diaretylacetone
a&
acetic acid on continlted reflclx-
Acetic acid (20 ml) was added to titanium dichloride diacetylacetone (0.95 g). The compound dissolved in the acid on refluxing. After refluxing for two hours, the compound decomposed and a yellowish white solid separated. After eight hours, the evolution of hydrogen chloride gas ceased. The mixture was cooled, the supernatant liquid decanted, and the compound dried under reduced pressure at room temperature. A yellowish white solid (0.47 g) was obtained. Found: Ti, 22.02; OAc, 72.14:~. Calcd. for equimolar mixture of TiO(OAc)s and O/:Ti(0,4c)&: Ti, 22.2; OAc, 72.83%.
486
D. M. PURI,
K. C. PANDE,
R. C. MEHROTRA
ACKNOWLEDGEMENTS
One of us (D.M.P.) is grateful to the Scientific Research Committee, U.P., for a Research Assistantship, during the tenure of which this work was carried out. REFERENCES 1 A. ROSENHEIM, W. LOEWENSTAMM AND L. SINGER, Ber. de&. them. Ges., 36 (1903) 1833. a W. DILTHEY, Ber. de&. them. Ges., 37 (1904) 588. 3 I. D. VARMA AND R. C. MEHROTRA, 1. pmkt. Chem., 8 (1959) 64. 4 I. D. VARFAA AND R. C. MMEHROTRA,J. pvakt. Chem., 8 (1959) 235. 5 I. D. VARMA .%ND R. C. MEHROTRA, J. Less-Common Metals, 3 (1961) 321. 6 K. C. PANDE AND R. C. MEHROTKA, J. prakt. Chem., 5 (1957) IOI. 7 R. N. KAPOOR, K. C. PANDE AND R. C. MEHROTRA, J. Indian. Chem. SW., 35 (1958) 151. 8 D. M. PURI AND R. C. MEHROTKA, J. Less-Comlnon Metals, 3 (1961) 247. 9 R. C. MEHROTRA, J. Indian. Chew. Soc., 30 (1953) 731. 10 A. YAMAMOTO AND S. KAMBARA, J. Am. Chem. Sot., 79 (1957) 4344. XI. R. C. YOUNG, Inorg. Syntheses, 20 (1946) 119. 1% T. G. BONNER AND M. P. THORNE, Amzlyst, 7g (1954) 759. *a J. S. JENNINGS, W. WARDLAW AND W. J. R. WAY, J, Chwn. SW., (1936) 637. D. C. BRADLEY, D. C. HANCOCK AND W. WARDLAW, J. Chem. Sot., (1g.p) 2773.
J. Less-Common
Metals, 4 (1962) 481-486