Chemistry Reference
In-Depth Information
Table 9 Topological metal-metal (M-M
0
) bond properties, source function percentage contribu-
tion from metals to the M-M
0
bond critical point, and M-M
0
delocalization indices in a number of
binuclear 3
d
and 4
d
metal complexes
a
M.
x
.FBO.
nb
b
r
b
10
2
2
r
b
10
2
jV
b
j
/
G
b
G
b
/
r
b
H
b
10
2
R
M-M
0
˚
r
H
b
/
r
b
q(M) S%
(M)
d
(M,M
0
)
Saturated binuclear 3
d
metal carbonyls, M
2
(CO)
x
Mn.10.1.0 2.949
0.71
0.27 0.952
25.0 0.285
2.62
0.27
1.91
0.29
4.80*
c
1.34
0.28 0.862
5.2 0.355
Fe.9.1.3
2.515
9.30
1.36
0.77
4.61*
c
Co.8.1.2
2.548
8.72
1.37
0.75
1.29
0.28 0.705
0.6 0.356
Co.8.1.0
2.691
3.61
0.20
1.95
0.35
1.19
0.33 0.658
4.4 0.437
3.70*
c
Ni.7.1.1
2.663
6.21
1.36
0.65
0.86
0.23 0.609
4.5 0.226
Unsaturated binuclear Co metal carbonyls, Co
2
(CO)
x
Co.7.2.0
2.486
4.94
3.77
1.67
0.57
1.89
0.38 0.636
7.3 0.394
5.79*
c
Co.7.2.1
2.394
8.55
1.50
0.74
2.17
0.37 0.645
14.6 0.783
Co.6.3.2
2.254
7.19
15.31
1.40
0.90
2.61
0.36 0.616
18.5 0.726
Co.5.4.1
2.168
7.85
23.56
1.31
1.09
2.70
0.34 0.530
27.9 0.976
M
2
(formamidinate)
4
binuclear 4
d
metal complexes, M
2
(HNCHNH)
4
Nb.4.3.4
2.284
13.00
35.46
1.37
1.07
5.09
0.39 1.413
40.4 2.507
Mo.4.4.4
2.141
16.57
51.79
1.36
1.22
7.33
0.44 1.360
40.6 2.930
Tc.4.3.4
2.122
16.40
50.16
1.36
1.20
7.08
0.43 1.208
40.8 2.713
Ru.4.2.4
2.540
7.32
6.59
1.63
0.61
2.81
0.38 1.042
28.2 1.316
Rh.4.1.4
2.501
7.27
6.93
1.61
0.61
2.71
0.37 0.962
29.3 1.035
Pd.4.0.4
0.13 0.815 17.1 0.294
a
Data from [
14
]. If not otherwise stated, all quantities in au. V
b
,G
b
, and H
b
are the potential energy
density, the positive-definite kinetic energy density, and the energy density at the M-M bcp or at
the M-M midpoint (see point c)
b
Each studied system is denoted as M.x.FBO.nb, where M is the metal,
x
the total number of
ligands in the complex, FBO the formal M-M bond order based on the 18-electron rule, and nb the
number of bridged ligands, with nb
2.730
4.16
14.99
1.12
1.04
0.53
0 in the case of an unbridged system. For the isostructural
M
2
(formamidinate)
4
binuclear 4
d
metal complexes,
x
and nb are fixed to 4, while the FBO varies
from 0 in the Pd compound to 4 in the Mo complex. For those systems, Ni.7.1.0 and Co.7.2.0, with
two nonequivalent M atoms, averaged M atom values are reported for FBO,
q
(M) and S%(M)
c
The asterisk, if present, denotes metal complexes lacking an M-M bcp. If this occurs, properties
are evaluated at the M-M midpoint or, for the S%(M) value, using this point as the rp
¼
compounds determining a negative contribution to the density at bcp and with the
carbonyl groups largely compensating such a density subtraction from the bcp. The
smaller negative S%(bcp,M) in Co.8.1.0 complies with a larger
d
(M, M
0
) value
(0.437 vs. 0.285) and a smaller net charge on the metal (
q
(M)
0.658 vs. 0.952) in
this compound. The net charge on the M atom decreases along the whole series with
the decrease in the number of linked ligands, and the S%(bcp or mp,M) values
correspondingly increase, when the trends for the bonded and not bonded systems
are examined separately. In fact both the ligands and, in particular, the M-M
bonding concur in decreasing the S%(M)
19
value, as discussed earlier by comparing
¼
19
S%(M) is here used for either S%(bcp,M) or S%(mp,M) according the system has or not has an
M-M bcp.
