Self-assembled Transition Metal Coordination Frameworks of ...

Ligands
The C-S bond distances of 1.6571(2) A in molecule A and 1.6507(3) A in
molecule B agree well with those in related compounds [9,3l,32] being intermediate
between 1.82 A for a C-S single bond and 1.56 A for a C=S double bond [11]. The
C(ll)—N(3) and C(ll)—N(4) bond distances in both molecules are, intermediate
between 1.47 A for a C—N single bond and 1.29 A for a C=N double bond [33],
indicative of some electron delocalization. Similarly the N(2)—N(3) [l.3545(2) A and
1.3580(2) A in molecules A and B respectively] and N(4)—N(5) [l.3663(2) A and
1.3648(3) A in molecules A and B respectively] bond distances are, intermediate
between 1.45 A for a N—N single bond and 1.25 A for a N=N double bond [33], also
indicative of extensive electron delocalization in the whole thiocarbohydrazone
moiety. The extensive electron delocalization is similar to that seen in bis(2­
benzoylpyridine) thiocarbohydrazone [11].
Each molecule is stabilized by three intramolecular hydrogen bonds. The
intramolecular N(3)—H(3)---N(1) and N(4)—H(4)---N(6) hydrogen bonds form six­
membered N(1)—C(9)—C(10)—N(2)—N(3)—H(3) and N(6)—C(13)—C(12)—N(5)—N(4)—
H(4) rings respectively in both A and B molecules; while the intramolecular hydrogen
bond N(4)—H(4)---N(2) forms a five-membered N(2)—N(3)—C(11)—N(4)—H(4) ring in
both A and B molecules (Fig. 2.16 & Table 2.5). The thiocarbohydrazone moieties
viz. C(10)/N(2)/N(3)/C(1 1)/ S(1)/N(4)/N(5)/C(12) in A and B show some variations in
planarity, as evidenced by a maximum deviation of0. 101(3) A for N(4A) in molecule
A and a maximum deviation of 0.028(3) A for N(2B) in molecule B. This clearly
shows that the central thiocarbohydrazone core is almost planar in molecule B and a
slight deviation from planarity for the same core of molecule A. However the
thiocarbohydrazide core N(2)/N(3)/C(l1)/S(1l)/N(4)/N(5) of molecule A is almost
planar with a maximum deviation of -0.055(3) A for N(4A).
61