Chemistry Reference
In-Depth Information
X
O
Y
Y
X
S
Au
P
Y
X
X
X = OCOCH
3
Y = CH
2
CH
3
FIGURE 4.1A
2D structure of auranofin.
FIGURE 4.1B
3D structure of auranofin without hydrogen atoms.
NH
3
0.751
1.179
Cl
Pt
Cl
Cl
Pt
Cl
-0.45
0.00
-0.08
0.16
NH
3
FIGURE 4.2
Cisplatin and platinum chloride.
conventional manner. After geometry optimization, one calculated a bond order
B
=
1.476 (typical aromatic) for the S-Au bond, and a bond order B
=
1.085 for the
Au-P bond (value situated at the limit between a single and aromatic bond). The
other chemical bonds were calculated as single bonds. Since it does not include coor-
dinative bonds (see Table 4.1), auranofin is considered here an organometallic com-
pound, not an organometallic complex.
Tetraethyl lead (Et
4
Pb) and Grignard compound Ph-Mg-Br are modeled as organo-
metallic compounds also, because B
C-Pb
= 0.876, B
C-Mg
= 0.833, and B
Mg-Br
=
0.779.
Figure 4.2 presents the planar structure of cisplatin, a compound used in anti-
cancer therapy (ChemIDplus/b). The calculated values of the bond orders (trun-
cated at three decimal places) and the calculated values of the net charges (two
decimal places) are noted in the figure. For comparison, the same values in PtCl
2
are shown in Figure 4.2. The reader can see the significant decrease of the val-
ues of the bond orders of the Pt-Cl bonds and of the net charges of the Pt and Cl
atoms, because of presence of the NH
3
ligand. The value of B for the Pt-N bond was
