Chemistry and Uses of Titanium Organic Compounds - ACS Publications

Chemistry

and

Uses

of

Titanium

Organic Compounds

JOHN H. HASLAM

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on November 18, 2014 | http://pubs.acs.org Publication Date: January 1, 1959 | doi: 10.1021/ba-1959-0023.ch025

Pigments Department, Ε. I. du Pont de Nemours & Co., Inc., Wilmington, Del.

Tetraortho esters of titanium are produced by the reaction of titanium tetrachloride, alcohol, and am monia. The physical and chemical properties of the n-alkyl and branched-chain titanates are discussed among others in the light of the coordination behavior of titanium. The esters are chemically reactive, un dergoing hydrolysis, alcoholysis, acidolysis, and ester exchange reactions readily. Titanium chelates and acylates can be prepared from titanium esters. The chelates are much less reactive than the esters, but usually undergo the same reactions at higher tem peratures. The acylates are polymers of low molecu lar weight. The uses of alkyl titanates in the paint, bonding, catalysis, and water repellency fields are stressed with emphasis on the distinct property which renders them acceptable.

The first titanium organic compound produced was the ethyl ester prepared in 1875 by Demarcay (14) from titanium tetrachloride and sodium ethylate. There is some question as to whether tetraethyl titanate was obtained, but there seems little doubt that a condensed ester, at least, was prepared. In 1892 Levy (39) published an exten sive paper describing the synthesis and properties of tetraphenyl titanate and other aryl titanates and also described attempts to produce titanium alkyls by reaction of titanium tetrachloride or titanium metal with zinc, aluminum, and mercury alkyls. In 1924 Bischoff and Adkins (3) described the synthesis of tetraisopropyl titanate and tetra-n-butyl titanate. Little industrial attention was given titanium organics until 1947, when Kraitzer, McTaggart, and Winter (35) described a high temperature paint produced from tetrabutyl titanate and aluminum flake. At about this time titanium tetrachloride began to be produced in large quantities incidental to titanium metal and titanium dioxide pigment manufacture. This large volume supply of titanium tetrachloride provided the impetus for industrial research on titanium organics and for the last 10 years an increasing amount of research has been devoted to titanium organics of a variety of types. These efforts have not led as yet to any large scale uses, but have developed a number of small industrial appli cations in a wide variety of fields. 272

In METAL-ORGANIC COMPOUNDS; Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

273

H ASLAM—TITAN IUM ORGANIC COMPOUNDS T i t a n i u m Esters


T h e p h y s i c a l a n d c h e m i c a l p r o p e r t i e s o f t i t a n i u m esters a r e i n f l u e n c e d t o a large e x t e n t b y t h e f a c t t h a t t i t a n i u m has a m a x i m u m c o o r d i n a t i o n n u m b e r of 6, t w o m o r e t h a n its m a x i m u m valence. T h e structure of a tetraortho ester:

i l l u s t r a t e s t h e o c t a h e d r a l s t r u c t u r e t h e ester is c a p a b l e of a s s u m i n g , i f i t h a s a c o o r d i n a t i o n n u m b e r of 6. T h e t w o p o t e n t i a l s e c o n d a r y b o n d s f o r m i f a n e l e c t r o n - d o n a t i n g a t o m s u c h as o x y g e n o r n i t r o g e n is a v a i l a b l e . T h u s , esters w h i c h h a v e u n s h i e l d e d o x y g e n a t o m s a r e l a r g e l y associated (9, 10, 12) a n d s h o w u n e x p e c t e d l y h i g h b o i l i n g p o i n t s , densities, viscosities, a n d r e f r a c t i v e i n d i c e s . T h e f o r m a t i o n of i n t e r m e d i a t e c o m p l e x e s w i t h v a r i o u s m a t e r i a l s s u c h as w a t e r , a l c o h o l , o r g a n i c esters, a n d acids u n d o u b t e d l y is t h e m e c h a n i s m b y w h i c h t i t a n i u m esters r e a d i l y u n d e r g o r e a c t i o n w i t h these c o m p o u n d s . T h e c o m p a t i b i l i t y of t i t a n i u m esters w i t h s u c h a w i d e v a r i e t y of p o l a r solvents is d u e t o a s s o c i a t i o n w i t h these s o l v e n t s a n d t h e s u r f a c e a c t i v i t y e x h i b i t e d b y t i t a n i u m esters is caused b y t h e i r a t t r a c t i o n t o p o l a r s u r faces. T h e fact t h a t t h e m a x i m u m c o o r d i n a t i o n n u m b e r o f t i t a n i u m i s h i g h e r t h a n i t s valence does n o t m a k e i t u n i q u e a m o n g m e t a l s . T h i s s i t u a t i o n exists w i t h m o s t m e t a l s ; b u t a c o m b i n a t i o n of a m a x i m u m c o o r d i n a t i o n n u m b e r of 6 a n d o f steric effects d u e t o t h e r e l a t i v e l y s m a l l size o f t h e t i t a n i u m a t o m w i t h f o u r g r o u p s s u r r o u n d i n g i t ( d u e t o i t s valence) does p r o v i d e a c e r t a i n u n i q u e n e s s . Z i r c o n i u m esters w i t h a v a l e n c e of 4 a n d m a x i m u m c o o r d i n a t i o n n u m b e r o f 8 a n d a l u m i n u m esters w i t h a v a l e n c e of 3 a n d m a x i m u m c o o r d i n a t i o n n u m b e r o f 6 f o r m s e c o n d a r y b o n d s m u c h m o r e e x t e n s i v e l y a n d t e n a c i o u s l y t h a n d o t i t a n i u m esters, t h u s h a v i n g n o t i c e a b l y different p h y s i c a l a n d c h e m i c a l p r o p e r t i e s . S i l i c o n does n o t u s u a l l y c o o r d i n a t e h i g h e r t h a n i t s v a l e n c e (except w i t h fluorine) a n d s i l i c o n esters a r e t h e r e f o r e m u c h less r e a c t i v e c h e m i c a l l y t h a n t i t a n i u m esters a n d h a v e v e r y different p h y s i c a l p r o p e r t i e s . T h e p r o p e r t i e s of t i t a n i u m esters l i e b e t w e e n those o f a l u m i n u m a n d z i r c o n i u m esters o n one h a n d a n d s i l i c o n o n t h e o t h e r . Production of T i t a n i u m Esters. T i t a n i u m esters are p r e p a r e d f r o m t i t a n i u m t e t r a c h l o r i d e , a l c o h o l , a n d a base. T h e r e a c t i o n of t i t a n i u m t e t r a c h l o r i d e w i t h a l c o h o l alon? w i l l n o t proceed beyond the replacement of t w o chlorine atoms. T i C l + 2 R O H -> T i C l ( O R ) + 2HC1 4

2

(1)

2

T h e a d d i t i o n of a c i d a c c e p t o r s s u c h as s o d i u m a l c o h o l a t e , a m m o n i a , o r a m i n e s results i n t h e f o r m a t i o n o f t h e t e t r a e s t e r . I n d u s t r i a l l y , t h e N e l l e s process (40) u t i l i z i n g a m m o n i a is used. T i C l + 4 R O H + 4 N H -> T i ( O R ) + 4NH C1 4

3

4

4

(2

T h e r e a c t i o n i s e x o t h e r m i c a n d e x t e r n a l c o o l i n g i s necessary. U s u a l l y the reaction is carried o u t i n a h y d r o c a r b o n solvent f r o m w h i c h the insoluble a m m o n i u m chloride is r e m o v e d b y f i l t r a t i o n . T h e s o l v e n t is d i s t i l l e d off a n d t h e r e s i d u a l t i t a n i u m ester i s v a c u u m distilled. V a r i a t i o n s o f t h i s process h a v e been p a t e n t e d i n w h i c h t h e r e a c t i o n i s c a r r i e d o u t i n l i q u i d a m m o n i a (28) o r s o l v e n t s s u c h as f o r m a m i d e (29). I n these cases t h e a m m o n i u m c h l o r i d e is soluble i n t h e s o l v e n t , b u t t h e t i t a n i u m ester separates as a d i s t i n c t layer. A l c o h o l s s u c h as i e r i - b u t a n o l o r a l l y l a l c o h o l w h i c h react r e a d i l y w i t h h y d r o c h l o r i c a c i d t o p r o d u c e the a l k y l c h l o r i d e a n d w a t e r d o n o t g i v e t i t a n i u m esters b y t h i s process, because the w a t e r f o r m e d h y d r o l y z e s the p r o d u c t . T i t a n i u m esters o f s u c h alcohols a r e


274

ADVANCES IN CHEMISTRY SERIES

best p r o d u c e d b y first s a t u r a t i n g t h e t i t a n i u m t e t r a c h l o r i d e w i t h a m m o n i a t o o b t a i n the c o m p l e x a n d r e a c t i n g t h i s w i t h t h e a l c o h o l TiCl TiCl -8NH 4


Table I. M.P.,

4

°C.

210 >25 20 — —

—

T i ( O R ) O A c + R O A c 2

3

(16)

Ο

Ti(OR)

4

(17)

Ο -> T i ( O R ) 0 C / X

+

3

Ο

2

ROaCN/'

F u r t h e r r e a c t i o n m a y t a k e p l a c e a n a l o g o u s l y t o R e a c t i o n s 10 a n d 1 1 . Reaction with Organic Esters. W i t h o r g a n i c esters, t i t a n i u m esters ester exchange r e a c t i o n s r a p i d l y a t e l e v a t e d t e m p e r a t u r e s . Ti(OR)

4

+ 4 R ' C 0 R " ^± T i ( O R " ) 4 + 4 R ' C 0 R 2

Reaction with Silicones a n d Silicols.

2

Silicols react like alcohols w i t h


undergo

(18) titanium

H AS LAM—ΤIΤΑ ΝIU M ORGANIC COMPOUNDS

277

esters. T h u s , i s o p r o p y l t i t a n a t e a n d f o u r m o l e s of t r i p h e n y l s i l a n o l give t e t r a k i s ( t r i p h e n y l s i l y l ) t i t a n a t e . W i t h s i l a n e d i o l s , c o p o l y m e r s c a n be p r o d u c e d {20). ORPh Ti(OR)

4

+ Ph Si(OH) 2

2

—TiOSiO-

I

I

+ 2ROH

(19)

OR Ph


T i t a n i u m esters i n c a t a l y t i c a m o u n t s a r e effective c u r i n g agents f o r some silicone resins {34). L o w t e m p e r a t u r e c u r i n g f o r silicone t e x t i l e w a t e r r e p e l l e n t s c a n b e a c c o m p l i s h e d b y t i t a n i u m ester c a t a l y s t s {19). T i t a n i u m esters a r e used w i t h silicones as w a t e r r e p e l l e n t s f o r l e a t h e r {13). I n t h i s case no c h e m i c a l r e a c t i o n seems t o be i n v o l v e d a n d t h e a c t i o n of t h e t i t a n i u m ester m a y be one of s u r f a c e a c t i v i t y t o p r o v i d e b e t t e r w e t t i n g of t h e l e a t h e r fibers. Catalysis b y T i t a n i u m Esters. T i t a n i u m esters a r e excellent ester exchange c a t a l y s t s f o r r e a c t i o n s b o t h b e t w e e n a n o r g a n i c ester a n d a n a l c o h o l a n d b e t w e e n t w o o r g a n i c esters. Ti(OR)

R C0 R + R ' O H

%

R'C0 R + R"C0 R"'

%

,

2

R'C0 R" + ROH

2

(20)

2

Ti(OR) 2

4

4

R'C0 R"' + R"C0 R 2

2

(21)

T a b l e I I gives t h e c o m p a r a t i v e rates of e t h a n o l p r o d u c t i o n i n t h e r e a c t i o n of e t h y l benzoate w i t h b u t a n o l a n d various catalysts.

Table II.

Reaction of Ethyl Benzoate with Butanol

Catalyst Used Tetraisopropyl titanate Aluminum triisopropoxide Sodium ethylate Tetraethyl silicate Tetrabutyl zirconate Tributyl borate

Concn., % 5 5 5 5 5 5

Rate of E t O H Removal, C c . / H r . >280 70 50 10 0 0

T i t a n i u m esters a r e e n j o y i n g i n c r e a s i n g c o m m e r c i a l use as c a t a l y s t s i n ester e x change r e a c t i o n s . A l d o l c o n d e n s a t i o n s a r e effected b y t i t a n i u m esters {26). A s o l u t i o n of t e t r a i s o p r o p y l t i t a n a t e i n acetone, a l l o w e d t o s t a n d f o r s e v e r a l d a y s a t r o o m t e m p e r a t u r e , w i l l show deposits of c r y s t a l s of t h e t i t a n a t e of d i a c e t o n e a l c o h o l . A t h i g h e r t e m p e r a t u r e s , t h e r e a c t i o n goes m o r e r a p i d l y t o p r o d u c e d i a c e t o n e a l c o h o l , t r i a c e t o n e d i alcohol, a n d / o r m e s i t y l oxide. T i t a n i u m esters c a t a l y z e M e e r w e i n - P o n n d o r f r e a c t i o n s , b u t d o n o t seem t o b e as effective as a l u m i n u m esters. H o w e v e r , b e n z a l d e h y d e a n d i s o p r o p y l t i t a n a t e g i v e n e a r q u a n t i t a t i v e y i e l d s of d i b e n z a l a c e t o n e . T h e f o r m a t i o n of t h i s c o m p o u n d m u s t i n v o l v e first a M e e r w e i n - P o n n d o r f r e a c t i o n t o p r o d u c e acetone, f o l l o w e d b y a n a l d o l c o n d e n s a t i o n of t h i s w i t h b e n z a l d e h y d e a n d d e h y d r a t i o n t o d i b e n z a l a c e t o n e . Pyrolysis of T i t a n i u m Esters. T i t a n i u m esters p y r o l y z e a t t e m p e r a t u r e s of a r o u n d 3 5 0 ° C . a n d h i g h e r . T h e p r i m a r y d e c o m p o s i t i o n p r o d u c t s w i t h i s o p r o p y l t i t a n a t e seem t o be p r o p y l e n e , i s o p r o p y l a l c o h o l , a n d t i t a n i u m d i o x i d e . If the pyrolysis is carried out b y i m p i n g i n g a n a i r stream (or nitrogen) con t a i n i n g a l o w c o n c e n t r a t i o n of t e t r a i s o p r o p y l t i t a n a t e v a p o r o n a h o t surface ( 5 0 0 ° t o 6 0 0 ° C ) , a c l e a r t i t a n i u m d i o x i d e f i l m c a n be d e p o s i t e d . S u c h films a r e c o n s i d e r a b l y h a r d e r t h a n those p r o d u c e d b y h y d r o l y s i s of t i t a n i u m esters a n d c o n t a i n n o r e s i d u a l organic m a t t e r . T i t a n i u m d i o x i d e films p r o d u c e d b y p y r o l y s i s of t i t a n i u m esters s h o w p r o m i s e as s c r a t c h - r e s i s t a n t c o a t i n g s o n glass c o n t a i n e r s .


278


Titanium Chelates T i t a n i u m chelates f o r m e d i n aqueous s y s t e m s s u c h as t i t a n i u m o x a l a t e , t i t a n i u m g l y c o l a t e (86), a n d g l y c e r y l t i t a n a t e (4) h a v e b e e n k n o w n f o r a n u m b e r of y e a r s . They h a v e n o t f o u n d c o m m e r c i a l use. M o r e r e c e n t l y a t t e n t i o n h a s t u r n e d t o chelates f o r m e d

i n nonaqueous

systems.

T h e h e a t of f o r m a t i o n o f d i c h e l a t e s f r o m t e t r a i s o p r o p y l t i t a n a t e seems t o b e b e t w e e n 15 a n d 20 k c a l . T h e i r f o r m a t i o n t a k e s p l a c e r e a d i l y t h e r e f o r e , a n d t h e i r s y n t h e s i s u s u a l l y i n v o l v e s m e r e l y m i x i n g 2 m o l e s of l i g a n d w i t h 1 m o l e of t i t a n i u m t e t r a e s t e r .


I n these cases t h e l i g a n d s c o n t a i n h y d r o x y l g r o u p s w h i c h b y a l c o h o l y s i s r e p l a c e t w o a l k o x y g r o u p s o f t h e t i t a n i u m ester. A n e l e c t r o n - d o n a t i n g g r o u p i s o n t h e second o r t h i r d c a r b o n f r o m t h a t t o w h i c h t h e a l c o h o l g r o u p is a t t a c h e d , so t h a t a f i v e - o r s i x m e m b e r e d r i n g m a y b e f o r m e d w i t h t h e t i t a n i u m a t o m . S t r o n g chelates are f o r m e d b y g l y c o l s s u c h a s 2 - e t h y l h e x a n e - 1 , 3 - d i o l (5), b y d i k e t o n e s (17) s u c h as a c e t y l a c e t o n e , b y h y d r o x y a c i d s s u c h as l a c t i c , c i t r i c , a n d t a r t a r i c , b y ketoesters s u c h as a c e t o a c e t i c ester, a n d b y a m i n o a l c o h o l s s u c h as d i e t h a n o l a m i n e a n d t r i e t h a n o l a m i n e . W i t h g l y c o l s , a l c o h o l y s i s of b o t h h y d r o x y g r o u p s t o p r o d u c e p o l y m e r s is a c o m p e t i t i v e reaction t o chelate f o r m a t i o n . W i t h most glycols p o l y m e r f o r m a t i o n is suffi cient t o produce i n s o l u b i l i t y . W i t h 2-ethylhexane-1,3-diol (octylene glycol) l i n k i n g t o g e t h e r of t i t a n i u m a t o m s does t a k e p l a c e (42) b u t n o t t o a sufficient e x t e n t t o p r o duce i n s o l u b i l i t y . T i t a n i u m acetylacetonate, prepared f r o m isopropyl titanate, is a n orange-red c o m p o u n d of g o o d s t a b i l i t y w h i c h h y d r o l y z e s a c c o r d i n g t o R e a c t i o n 2 2 . TiAcac (OR) 2

2

+ 2 H 0 -> T i A c a c ( O H ) + 2 R O H 2

2

2

(22)

O n air d r y i n g , the d i h y d r o x y c o m p o u n d dehydrates a n d becomes insoluble. T i A c a c ( O I I ) -> [ — T i A c a c 0 — ] 2

2

2

x

+ II 0 2

(23)

T i t a n i u m l a c t a t e is a w h i t e s o l i d , e a s i l y s o l u b l e i n w a t e r , w h i c h f o r m s s t r o n g l y acidic solutions stable even a t prolonged b o i l i n g . T h e name t i t a n i u m lactate is a m i s n o m e r , because t h e c o m p o u n d i s n o t a salt o f l a c t i c a c i d .

II^CHCH

3

2[H]

+

1—OH

θ/-

\ CHXH 3

0

II ^C—0

T h e ionic structure accounts for its acidity i n solution. be s o m e w h a t p o l y m e r i z e d d u e t o d e h y d r a t i o n .

The dried compound

may

T r i e t h a n o l a m i n e t i t a n a t e l i k e o c t y l e n e g l y c o l t i t a n a t e i s n o t a definite c o m p o u n d ; because of t h e m u l t i p l i c i t y of h y d r o x y l g r o u p s , a c e r t a i n a m o u n t of l i n k i n g t o g e t h e r o f t i t a n i u m a t o m s exists. T r i e t h a n o l a m i n e t i t a n a t e is soluble i n t h e m o r e p o l a r s o l v e n t s s u c h as a l c o h o l a n d w a t e r . I t s w a t e r s o l u t i o n s a r e s t r o n g l y a l k a l i n e a n d h y d r o l y z e slowly a t room temperature. These solutions can be stabilized b y reducing t h e p H to a p p r o x i m a t e l y 8 w i t h carbon dioxide, phosphoric acid, o r various organic acids. I n g e n e r a l , t i t a n i u m chelates a r e m u c h less r e a c t i v e t h a n t i t a n i u m esters, b u t u s u a l l y u n d e r g o t h e same r e a c t i o n s a t h i g h e r t e m p e r a t u r e s . M o s t p o l y m e r s c o n t a i n i n g h y d r o x y l g r o u p s a r e c r o s s - l i n k e d i m m e d i a t e l y b y t i t a n i u m esters so t h a t w i t h these p o l y m e r s t w o - c o a t a p p l i c a t i o n s m u s t b e u s e d . W i t h t i t a n i u m chelates, however, m i x e d solutions of resin a n d chelate can be p r e p a r e d w h i c h have indefinite life, b u t w h i c h o n b a k i n g ( o r i n some cases a i r d r y i n g ) r e a c t t o p r o d u c e cross l i n k i n g . H i r t a n d B r u x e l l e s (31) h a v e d e s c r i b e d a s y s t e m w i t h n i t r o c e l l u l o s e a n d t i t a n i u m


279

HASLAM—TITANIUM ORGANIC COMPOUNDS

acetylacetonate w h i c h produces o n air d r y i n g a cross-linked film of i m p r o v e d p r o p e r ties. O c t y l e n e g l y c o l t i t a n a t e w i l l r e a c t s i m i l a r l y a n d has t h e a d v a n t a g e o f l i g h t e r color t h a n the t i t a n i u m acetylacetonate.


A l k a n o l a m i n e t i t a n a t e s h a v e been p a t e n t e d as c r o s s - l i n k i n g agents f o r e p o x y resins (2). V a r i o u s l i g a n d s a d d e d t o r e s i n - t i t a n i u m ester c o m p o s i t i o n s h a v e been found t o prevent p r i o r gelation of the solution. E t h y l lactate a n d ethylene glycol m o n o e t h y l e t h e r h a v e been d e s c r i b e d as effective w i t h cellulosics (1). T i t a n i u m l a c t a t e a n d p o l y ( v i n y l a l c o h o l ) f o r m s t a b l e m i x e d aqueous s o l u t i o n s . A f t e r a p p l i c a t i o n a s h o r t b a k e a t 80° t o 1 0 0 ° C . p r o d u c e s a f i l m w h i c h a l t h o u g h softened b y w a t e r is n o l o n g e r s o l u b l e i n w a t e r . S i m i l a r a p p l i c a t i o n s h a v e b e e n d e s c r i b e d w i t h p h e n o l i c resins, e p o x y resins, a l k y d s , a n d cellulosics (16, 44) > O c t y l e n e g l y c o l t i t a n a t e is a n effective s u r f a c e a c t i v e agent i n o r g a n i c s y s t e m s a n d is u s e d w i t h p a r a f f i n w a x i n t e x t i l e w a t e r r e p e l l a n t s (18). I t gives m o r e c o m p l e t e w e t t i n g o f t h e fibers i n t h e w a x s o l u t i o n a n d t h e r e f o r e i m p r o v e d w a t e r r e p e l l e n c y .

Titanium Acylates Preparation and Structure. T i t a n i u m t e t r a a c y l a t e s c a n be p r e p a r e d , b u t u n d e r g o slow decomposition a t r o o m t e m p e r a t u r e t o give the acid a n h y d r i d e a n d p o l y ( t i t a n y l diacylates). TiCl

+ 4 N a 0 C R -> T i ( 0 C R ) + 4 N a C l

4

2

2

(24)

4

0 CR" 2

Ti(0 CR) 2

4

. Poly(hydroxytitanyl s o l u t i o n s (87).

acylates)

+

—TiO—

(25)

(RCO) 0 2

2

_

—TiO—

+ R C0 R + 2ROH

(27)

+

(28)

,

2

I

Δ

or

OR Ti(OR)

4

+ R'C0 H + H 0 2

2

•

0 CR'" 2

3ROH

I —TiO— A l l of these p o l y ( t i t a n y l a c y l a t e s ) , o f l o w m o l e c u l a r w e i g h t , are p r o b a b l y m o s t l y cyclic structures. A l t h o u g h cryoscopic determ OiRn a t i o n s o f t e n s h o w n o m e a s u r a b l e d e p r e s s i o n i n t h e f r e e z i n g p o i n t o f t h e s o l v e n t , t h i s i s due t o a s s o c i a t i o n (as i n t h e case of esters) r a t h e r t h a n t o a h i g h degree o f p o l y m e r i z a t i o n . L i q u i d c o m p o u n d s o f t h i s t y p e s u c h as p o l y ( i s o p r o p o x y t i t a n y l oleate) are n o t v e r y v i s c o u s . A l l o f the p o l y ( t i t a n y l a c y l a t e s ) are v e r y soluble i n h y d r o c a r b o n s a n d o t h e r n o n p o l a r s o l v e n t s t o g i v e n o n v i s c o u s s o l u t i o n s e v e n a t 5 0 % o r a t h i g h e r c o n c e n t r a t i o n s ; t h e r e f o r e t h e degree o f polymerization must be low. Reactions. P o l y ( a l k o x y t i t a n y l a c y l a t e s ) are r e a d i l y h y d r o l y z e d t o p o l y ( h y d r o x y t i t a n y l acylates) b y contact w i t h water at room temperature.

I



280 Γ

-

0 CRH 2

0 CR' 2

_

J + ROH (29) + H 0-> —TiO— —TiO— j OH ζ X OR W h e n t h e a e y l a t e g r o u p is b u t y r i c or l a r g e r , f u r t h e r h y d r o l y s i s r e s u l t i n g i n t h e r e m o v a l o f t h e a e y l a t e g r o u p t a k e s place v e r y s l o w l y o r n o t a t a l l w i t h w a t e r alone. H o w e v e r , aqueous s o d i u m h y d r o x i d e s o l u t i o n s r a p i d l y a n d c o m p l e t e l y h y d r o l y z e a l l t i t a n i u m acylates. T h e p o l y ( a l k o x y t i t a n y l a c y l a t e s ) easily u n d e r g o a l c o h o l y s i s t o r e p l a c e t h e a l k o x y group.


2

0 CRH

Γ

2

+ R"OH :

-TiO-

I

0 CR' 2

-TiO-

_

+ ROH

(30)

I

OR" OR P o l y ( t i t a n y l d i a c y l a t e s ) also r e a d i l y u n d e r g o a c i d o l y s i s (25) •

0 CR • I —TiO—

0 CR'" 2

2

+ 2 R ' C 0 H ^±

I

2

I

-TiO—

+

2RC0 H 2

(31)

I

0 CR 0 CR' Uses. P o l y ( t i t a n y l a c y l a t e s ) are excellent surface a c t i v e agents a n d h a v e been e x a m i n e d as g r i n d i n g aids i n p i g m e n t m a n u f a c t u r e a n d as d i s p e r s a n t s f o r p i g m e n t s i n p a i n t s , i n k s , a n d p l a s t i c s . P o l y ( i s o p r o p o x y t i t a n y l stéarate) has s h o w n p r o m i s e as a water repellent for masonry. A c y l a t e s m a d e f r o m d r y i n g o i l acids s u c h as s o y b e a n o r linseed acids a i r d r y , b u t t h e films p r o d u c e d are n o t of g o o d q u a l i t y . T h e y h a v e been i n c o r p o r a t e d i n t o c o n v e n t i o n a l p a i n t coatings t o g i v e b e t t e r w e t t i n g a n d a d h e s i o n . 2

2

Organotitanium Compounds L e v y (39) d e s c r i b e d a t t e m p t s t o m a k e e t h y l t i t a n i u m i n 1892 a n d since t h e n m a n y o t h e r e x p e r i m e n t s h a v e been m a d e . A l l o f these e a r l y efforts r e s u l t e d i n a r e d u c t i o n i n t h e v a l e n c e of t i t a n i u m , a n d b i p h e n y l was i s o l a t e d i n w o r k i n v o l v i n g m e t a l lophenyl compounds. I t became apparent that quadrivalent t i t a n i u m compounds c o n t a i n i n g T i — C b o n d s were f o r m e d , b u t t h a t t h e y i m m e d i a t e l y d e c o m p o s e d t o g i v e lower valent t i t a n i u m and an organic radical. I n 1952 H e r m a n a n d N e l s o n (30) d e s c r i b e d t h e s y n t h e s i s o f t r i i s o p r o p o x y p h e n y l t i t a n i u m , a c o m p o u n d stable e n o u g h t o b e i s o l a t e d . T h e i r efforts t o p r o d u c e o t h e r a l k y l a n d a r y l t i t a n i u m i s o p r o p o x i d e s l e d t h e m t o t h e c o n c l u s i o n t h a t t h e s t a b i l i t y of the c o m p o u n d increased w i t h the electronegativity of the organo group. N o a l k y l t i t a n i u m c o m p o u n d s were f o u n d stable e n o u g h t o isolate. R e c e n t l y , the reaction products of t i t a n i u m tetrachloride a n d m e t a l alkyls have c o m e i n t o p r o m i n e n c e as c a t a l y s t s f o r t h e p r e p a r a t i o n o f l i n e a r p o l y e t h y l e n e (48). T h e s e c a t a l y s t s d o n o t differ m a t e r i a l l y f r o m t h e r e d u c e d t i t a n i u m c o m p o u n d s w h i c h h a v e r e s u l t e d f r o m the m a n y efforts t o s y n t h e s i z e o r g a n o t i t a n i u m c o m p o u n d s o v e r t h e y e a r s . T h e " n e w " c a t a l y s t s h a v e n o t been d e f i n i t e l y i d e n t i f i e d , b u t m a y b e a l k y l t i t a n i u m c o m p o u n d s where the v a l e n c e o f t i t a n i u m i s 2 o r 3. T i t a n i u m f o r m s stable " s a n d w i c h " c o m p o u n d s w i t h c y c l o p e n t a d i e n y l g r o u p s . D i c y c l o p e n t a d i e n y l t i t a n i u m d i c h l o r i d e (46) i s a stable, r e d c r y s t a l l i n e c o m p o u n d o f i o n i c c h a r a c t e r . I t is i n e r t t o w a t e r a n d c a n b e r e c r y s t a l l i z e d f r o m i t . D i c y c l o p e n t a d i e n y l t i t a n i u m d i p h e n y l (and other dicyclopentadienyl t i t a n i u m d i a r y l s ) h a v e b e e n p r o d u c e d (45) f r o m d i c y c l o p e n t a d i e n y l t i t a n i u m d i c h l o r i d e a n d p h e n y l l i t h i u m , b u t t h e s t a b i l i t y o f t h i s c o m p o u n d i s c o n s i d e r a b l y less t h a n t h a t o f the dichloride.


HASLAM—TITAN IUM ORGANIC COMPOUNDS

281

Literature Cited (1) Beacham, H . H . (to National Lead Co.), U. S. Patent 2,686,133 (Aug. 10, 1954). (2) Beacham, H . H., Merz, Κ. M . (to National Lead Co.), Ibid., 2,742,448 (April 17, 1956).

(3) Bischoff, F., Adkins, H., J. Am. Chem. Soc. 46, 256 (1924). (4) Booge, J. E . , Gulledge, H . C. (to Ε. I. du Pont de Nemours & Co.), U . S. Patent 2,468,916 (May 3, 1949).

(5) Bostwick, C. O. (to Ε. I. du Pont de Nemours & Co.), Ibid., 2,643,262 (June 23, 1953). (6) Bradley, D. C., Abd-el Halim, F. M., Wardlaw, W., Chem. and Ind. (London), 1951, Downloaded by UNIV OF CALIFORNIA SAN DIEGO on November 18, 2014 | http://pubs.acs.org Publication Date: January 1, 1959 | doi: 10.1021/ba-1959-0023.ch025

310.

(7) Bradley, D. C., Hancock, D. C., Wardlaw, W., J. Chem. Soc. 1952, 2773. (8) Bradley, D. C., Gaze, R., Wardlaw, W., Ibid., 1955, 721. (9) Bradley, D. C., Mehrota, R. C., Swanwick, J. D., Wardlaw, W., Ibid., 1953, 2025. (10) Bradley, D. C., Mehrota, R. C., Wardlaw, W., Ibid., 1952, 2027, 4204, 5020.

(11) Crowe, R. W., Caughlin, C. N., J. Am. Chem. Soc. 72, 1694 (1950). (12) Cullinane, Ν. M . , Chard, S. J., Price, G. F., Millward, Β. B., Langlois, G., J. Appl. Chem. (London) 1, 400 (1951). (13) Currie, C. C. (to Dow Corning Corp.), U . S. Patent 2,672,455 (March 16, 1954). (14) Demarcay, E., Compt. rend. 80, 51 (1875). (15) Eastman Chemical Products, Inc., Formulators' Notes No. 9 (May 25, 1955); Supple ment to No. 9 (Sept. 26, 1955). (16) Farben, Bayer. A.-G. Brit. Patent 734,114 (July 27, 1955). (17) Ibid., 734,113 (July 27, 1955). (18) Green, L. Q. (to Ε. I. du Pont de Nemours & Co.), U . S. Patent 2,628,171 (Feb. 10, 1953).

(19) Guillissen, C. J., Gancberg, Α., Ibid., 2,732,320 (Jan. 24, 1956). (20) Gulledge, H . C. (to Ε. I. du Pont de Nemours & Co.), Ibid., 2,512,058 (June 20, 1950).

(21) (22) (23) (24) (25) (26) (27) (28) (29)

Haslam, J. H . (to Ε. I. du Pont de Nemours & Co.), Ibid., 2,732,799 (Jan. 31, 1956). Ibid., 2,684,972 (Feb. 21, 1952). Ibid., 2,621,195 (Dec. 9, 1952). Ibid., 2,708,205 (May 10, 1955). Ibid., 2,708,203 (May 10, 1955). Ibid., 2,719,863 (Oct. 4, 1955). Ibid., 2,768,909 (Oct. 30, 1956). Herman, D. F. (to National Lead Co.), Ibid., 2,655,523 (Oct. 13, 1953). Ibid., 2,654,770 (Oct. 6, 1953).

(30) Herman, D. F., Nelson, W. K., J. Am. Chem. Soc. 74, 2693 (1952); 75, 3882 (1953).

(31) (32) (33) (34) (35) (36)

Hirt, R. P., Bruxelles, G. Ν., Ind. Eng. Chem. 48, 1325 (1956). Jennings, J. S., Wardlaw, W., Way, W. J. R., J. Chem. Soc. 1936, Part I, 637. Keil, J. W. (to Dow Corning Corp.), U . S. Patent 2,751,314 (June 19, 1956). Kin, M. (to Dow Corning Corp.), Ibid., 2,721,855 (Oct. 25, 1955). Kraitzer, T. C., McTaggart, F. K., Winter, G., Paint Notes 2 (9) 304 (1947). Langkammerer, C. M. (to Ε. I. du Pont de Nemours & Co.), U . S. Patent 2,453,520

(37) (38) (39) (40) (41)

Ibid., 2,489,651 (Nov. 29, 1949). Ibid., 2,621,193 (Dec. 9, 1952). Levy, M. L., Ann. chim. et phys. [6] 25, 433 (1892). Nelles, J. (to I. G. Farbenindustrie A.G.), U . S. Patent 2,187,821 (Jan. 23, 1940). Nesmeyanov, A. N., Freĭdlina, R. Kh., Brainina, Ε.M.,Bull. Acad. Sci. U.S.S.R. No. 6,

(42) (43) (44) (45) (46) (47) (48)

Reeves, R. E., Mazzeno, L. W., J. Am. Chem. Soc. 76, 2533 (1954). Sacks, G., Werther, F., Farbe u. Lack 61, 60 (1955). Schmidt, F. (to Farbenfabriken Bayer A.G.), U. S. Patent 2,680,108 (June 1, 1954). Summer, L., Uloth, R. H., J. Am. Chem. Soc. 76, 2278 (1954). Wilkinson, G., Birmingham, J. M., Ibid.,76, 4281 (1954). Winter, G., J. Oil&Colour Chem. Assoc. 36, No. 402 (1953). Ziegler, K., Holzkamp, E., Breil, H., Martin, H., Angew. Chem. 67, 541 (1955).

(Nov. 9, 1948).

861 (1954).

RECEIVED for review May 10, 1957. Accepted June 1, 1957.


Chemistry and Uses of Titanium Organic Compounds - ACS Publications

Recommend Documents