Chemistry Reference
In-Depth Information
IV
320
III
240
II
160
I
80
0
0.4
0.8
1.2
1.6
2.0
2.4
M(OPr
i
)
M
Molar ratio
(OPr
i
)
4
′
Figure 3.3
Titration between
M
0
OPr
i
4
and M
OPr
i
. Curve I: (Ž)
NaOPr
i
M
/4.77
vs
Zr
OPr
i
4
.
Pr
i
OH
M
/80.49; Curve II: (
) KOPr
i
M
/9.97
vs
Zr
OPr
i
4
.
Pr
i
OH
M
/43.011; Curve
III: (ž)NaOPr
i
M
/9.94
vs
Ti
OPr
i
4
M
/37.7; Curve IV: (ð) KOPr
i
M
/9.94
vs
Ti
OPr
i
4
M
/37.7.
R
R
R
O
O
RO
OR
RO
M
M
OR
RO
OR
O
Figure 3.4
Schematic
representation
of
a
nona-alkoxodimetal-
late(IV) ligand.
manner
188
that suits their preferred coordination states is remarkable. The possibilities
of the alkoxometallate(
IV
) ligands to function as simpler fM
OR
5
g
and fM
OR
6
g
2
also enhance their versatility in a remarkable manner, as revealed by their X-ray
crystal structural studies at an ever-increasing pace since 1984;
217
these have in
general confirmed the conclusions about their plausible structures on the basis of
simpler colligative, spectroscopic, and other physico-chemical studies. A number of
representative examples of these types of tetra-alkoxometallate(
IV
) (including a few
heterotermetallic) derivatives are listed in Table 3.4. and an attempt is made in the
following paragraphs to rationalize their structural features (see also Chapter 4).
