[TiF2(salen)] 2. A 30 cm3 aliquot of anhydrous CH2Cl2 was
deaerated with argon for ca. 15 min and then added to freshly
sublimed TiF4 (1.50 g, 12.1 mmol). This suspension was then
treated, with stirring, with thf (4.0 cm3, ca. 50 mmol) at Ϫ20 ЊC
over a period of ca. 5 min. Immediately, the TiF4 was consumed
resulting in a colourless solution after the addition was com-
plete. The solution was warmed to room temperature over
ca. 30 min and filtered to remove the small amount of undis-
solved impurities. An additional 75 cm3 of thf was added to aid
stirring during the subsequent reaction. A thf solution of
salen(TMS)2 (5.03 g, 12.2 mmol) was added to the [(thf)2TiF4]
and a yellow-orange solid precipitated. The mixture was heated
at 60–65 ЊC for ca. 1 h to give first a clear yellow solution then
a bright yellow microcrystalline solid precipitate. The mother-
liquor was then removed by filtration, the solid was washed
with hexane (2 × 20 cm3) to remove any unreacted ligand, and
dried in vacuo. This yielded 3.5 g of [TiF2(salen)] 2 with a fur-
ther 0.40 g (90% overall) of 2 crystallised as yellow cubes from
the filtrate in air at room temperature. 1H NMR (CDCl3): δ 4.13
(s, 4H, CH2), 6.98–6.83 (m, 4H, Ph), 7.52–7.43 (m, 4H, Ph) and
8.35 (s, 2H, CH). 19F NMR (CDCl3): δ 145.49 (s, 2F). FABϩ
MS: m/z 333 (100%, [TiF(salen)]ϩ), 352 (10, [TiF2(salen)]ϩ).
(CDCl3): δ 4.25 (s, 4H, CH2), 6.85–7.13 (m, 4H, Ph), 7.33–7.61
(m, 4H, Ph) and 8.45 (s, 2H, CH). EIϩ MS (70 eV): m/z 393
(100%, [TiBr(salen)]ϩ), 474 (10, [TiBr2(salen)]ϩ).
[TiI(salen)]2(ì-O) 6. Method A. Titanium() iodide (2.7 g,
4.9 mmol) was washed with toluene until the extracts were
colourless to remove any iodine impurities and dried in vacuo.
A suspension of the metal salt was then treated with
salen(TMS)2 (2.1 g, 5.1 mmol) and slowly yielded an orange-red
solution. The mixture was then refluxed for 45 min whereupon
an intense red coloured solution was observed and was quickly
followed by the precipitation of a reddish-brown solid with
some contamination by unreacted titanium() iodide. The mix-
ture was allowed to cool and the solvent was removed in vacuo
to give a red-brown solid. This was then extracted with hot
toluene (2 × 30 cm3) to remove the concomitant Me3SiI (not
isolated). The resulting brown solid was dried in vacuo and
subsequently washed with acetone to immediately give 6 as a
bright orange solid (Found: C, 43.7; H, 3.2; N, 6.4. Calc. for 6,
C32H28N4O5I2Ti2: C, 42.8; H, 3.1; N, 6.2%).
Method B. Titanium() iodide (4.05 g, 7.29 mmol) was
washed with hexane until the extracts were colourless to remove
traces of iodine and dried in vacuo. This was then added in two
portions to an acetonitrile solution (ca. 300 cm3) of salenH2
(1.95 g, 7.29 mmol) to immediately give an orange solution as
the metal salt dissolved. Within ca. 10 min the solution had
become dark brown in colour and a small quantity of brown
precipitate was seen. After refluxing for ca. 1 h the supernatant
was filtered in the air and after ca. 2 min 6 precipitated from
the solute as a bright orange microcrystalline solid. Washing
the brown filtrate with acetone immediately gave further 6. The
yield of 6 was ca. 3.0 g (46%) via method B.
[TiCl2(salen)] 3. In a typical preparation salenH2 (10.0 g, 37.3
mmol) in thf was treated dropwise with titanium() chloride
(1.0 M, 37.3 cm3, 37.3 mmol) with vigorous stirring. At once
orange [(thf)TiCl2(salen)] 4 precipitated from solution. This
mixture was then heated at reflux for ca. 45 min until all of the
orange solid, 4, was replaced by the dark red microcrystalline 3.
Solvent was then removed and the solid washed with acetone–
water (50:50) and then acetone and subsequently dried in
1
vacuo. The yield of 3 varies from 75–85%. H NMR (CDCl3):
δ 4.25 (s, 4H, CH2), 6.85–7.13 (m, 4H, Ph), 7.33–7.61 (m, 4H,
Ph) and 8.39 (s, 2H, CH). FABϩ MS: m/z 330 (10%, [Ti(᎐O)-
[TiCl2{(MeO)2salen}] 7. To a yellow acetonitrile solution of
(MeO)2salenH2 (3.0 g, 9.2 mmol) was added a toluene solution
of titanium() chloride (1.0 M, 9.2 cm3, 9.2 mmol). The red
solution was heated to ca. 80 ЊC for 1 h and on cooling resulted
in the precipitation of a black solid, 7. The supernatant red
solution was decanted and yielded ca. 0.20 g of 7 at Ϫ20 ЊC.
The solid residue was washed with an acetone–water (50:50)
mixture and dried in vacuo. The combined yield of 7 was 3.1 g
(ca. 80%). 1H NMR (CD2Cl2): δ 4.00 (s, 6H, MeO), 4.20 (s, 4H,
CH2), 7.00–7.20 (m, 6H, Ph) and 8.40 (s, 2H, CH).
᎐
(salen)]ϩ), 349 (15%, [TiCl(salen)]ϩ).
[(thf)TiCl2(salen)] 4. Titanium() chloride (1.0 M, 7.5 cm3,
7.5 mmol) was added to a yellow thf solution of salenH2 (2.01
g, 7.46 mmol) to immediately give an orange solid. The mixture
was then stirred at room temperature for ca. 3 h without any
further changes. The very pale orange supernatant was then
removed by filtration, the solid washed with thf and then dried
1
in vacuo to yield 4 (ca. 3.2 g) in quantitative yield. H NMR
(CDCl3): δ 1.85 (m, 4H, CH2), 3.80 (m, 4H, CαH2), 4.25 (s, 4H,
CH2), 6.80–7.20 (m, 4H, Ph), 7.40–7.60 (m, 4H, Ph) and 8.34
[TiCl2(salphen)] 8. A thf solution of salphenH2 (10.0 g, 31.6
mmol) was treated with titanium() chloride (1.0 M, 32 cm3, 32
mmol) to immediately yield a light brown solid. This suspen-
sion was then refluxed for ca. 45 min. After cooling the solid
was filtered off and washed with copious quantities of acetone
and dried at 75 ЊC. The yield of 8 (13.6 g) was quantitative.
(s, 2H, CβH). FABϩ MS: m/z 330 (10%, [Ti(᎐O)(salen)]ϩ), 349
᎐
(15%, [TiCl(salen)]ϩ).
[TiBr2(salen)] 5. Method A. Titanium() bromide (8.1 g, 22
mmol) was dissolved in toluene and the red solution was filtered
to remove a small amount of undissolved material. This was
then added, over a period of ca. 30 min, to salenH2 (5.9 g, 22
mmol) in thf giving a red-orange solid precipitate. The mixture
was then heated for 45 min at 70 ЊC resulting in the precipi-
tation of a deep red microcrystalline solid. The mother-liquor
was removed by filtration and the solid washed thoroughly with
cold acetone and dried to yield 8.5 g of 5. The mother-liquor
was allowed to stand in the air at room temperature giving a
further 0.7 g (90% overall) of 5 as long, deep red needles.
Method B. TiBr4 (4.01 g, 10.9 mmol) was dissolved in toluene
and was added, over a period of ca. 15 min, to a solution of
salen(TMS)2 (4.50 g, 10.9 mmol) in thf. At once, an orange-red
precipitate formed. With continued stirring the reactants were
then heated at 65 ЊC for ca. 30 min, a deep red solution and
a microcrystalline deep red solid quickly precipitated. The
mother-liquor was then decanted from the solid which was
washed with toluene (3 × 30 cm3) to remove any unreacted
starting materials and the concomitant Me3SiBr. After drying
in vacuo and washing with cold acetone 5 was dried in an oven
overnight at 75 ЊC. This gave a yield of 4.85 g (95%). 1H NMR
FABϩ MS: m/z 413 (15%, [Ti(᎐O)Cl(salphen)]ϩ.
᎐
[TiCl2{(MeO)2salphen}] 9. To an orange thf solution of
(MeO)2salphenH2 (3.0 g, 8.0 mmol) was added a toluene
solution of titanium() chloride (1.0 M, 8.0 cm3, 8.0 mmol).
During the addition a black solid precipitated. The mixture was
refluxed for 1 h and subsequently cooled overnight to yield a
black microcrystalline solid and a dark red solution. Decanting
the supernatant, washing the solid with cold acetone (3 × 50
cm3) and drying at 75 ЊC gave 3.2 g of impure 9. A further 200
mg of the complex was recovered from the filtrate (85% over-
1
all). H NMR (CD2Cl2): δ 4.00 (s, 6H, MeO), 7.10–7.70 (m,
10H, Ph) and 8.90 (s, 2H, CH). FABϩ MS: m/z 423 (10%,
[Ti{(MeO)2salphen}]ϩ, protonated).
[TiCl4(dmsalenH2)] 10. A toluene slurry of dmsalenH2 (2.0 g,
6.8 mmol) was treated with a toluene solution of titanium()
chloride (1.0 M, 7.0 cm3, 7.0 mmol) to instantly give a red-
orange solid. The mixture was then stirred for a further 3 h with
no further changes. The colourless solvent was then removed by
J. Chem. Soc., Dalton Trans., 1998, 3489–3494
3493