M. Das et al. / Inorganic Chemistry Communications 14 (2011) 1337–1340
1339
time that the salen type compartmental Schiff base N,N′-(1,2-
Phenylene)-bis(3-methoxysalicylideneimine), which was hitherto
used to prepare dinuclear compounds only, can also be used to
synthesise trinuclear compounds as well. Such bonding mode was
unprecedented for the ligand. Thus it opens up new possibilities for
the synthesis of such type of compounds.
Acknowledgements
This work was supported by the University Grants Commission,
CAS-UGC, New Delhi.
Appendix A. Supplementary material
Crystallographic data for the analysis have been deposited with
the Cambridge Crystallographic data Centre, CCDC No 805837. The
Fig. 2. Trigonal dodecahedral geometry of Na+ in compound 1.
are almost orthogonal. Both the Ni atoms are four-coordinated in an
approximately square-planar geometry constructed by two imine N
atoms and two phenolate O atoms. Sum of the different angles around
the Ni atoms is almost 360° [360.07 for Ni(1) and 360.1for Ni(2)]
indicating very slightly distorted square-planar geometry around the
Ni atoms. The distortion may conveniently be measured by the trans
angles that are ideally 180° for a square-planar compound and 109.5°
in a tetrahedral compound. The trans angles are found to be 177.1(6)
{O(2)–Ni(1)–N(1)}, 176.1(6) {N(2)–Ni(1)–O(2)}, 174.9(6) {O(6)–Ni
(2)–N(4)} and 177.7(8) {O(7)–Ni(2)–N(3)}. Deviations of the
coordinating atoms O(2), O(3), N(1) and N(2) for Ni(1) fragment
from the least-square mean plane through them are −0.039(10),
0.040(9), 0.039(15), and −0.040(13) Å respectively. For Ni(2)
fragment, deviations of the coordinating atoms O(6), O(7), N(3) and
N(4) from the least-square mean plane through them are −0.049
(11), 0.049(10), 0.05(2), and −0.048(17) Å respectively. The intra-
molecular separations between Ni(1)···Ni(2) is 7.18 Å, whereas Ni
(1)···Na(1) and Ni(2)···Na(1) separations are 3.614 Å and 3.601 Å
respectively. None of these distances are sufficiently short to imply
any metal–metal bonding or to allow intra-metal spin exchange
through mutual interaction. The {Ni(1)–O(2)–Na(1)}, {Ni(1)–O(3)–
Na(1)}, {Ni(2)–O(6)–Na(1)} and {Ni(2)–O(7)–Na(1)} angles are
110.0(5), 109.0(4), 109.6(5) and 110.4(5) respectively.
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[28] The ligand, H2L, was synthesised by refluxing
a methanol solution of o-
phenylenediamine (108 mg, 1 mmol) and 3-methoxysalicylaldehyde (304 mg,
2 mmol) in 1:2 molar ratios for 1 h. It was then used directly without further
purification. To prepare compound 1, a methanol solution (10 ml) containing Ni
(ClO4)2•6H2O (365 mg, 1 mmol) and NaClO4 (230 mg, 1 mmol) was added to a
methanol solution (20 ml) of the ligand, H2L (1 mmol) in refluxing condition. Red
crystalline compound started to separate from the solution after about 15 min. All
the starting materials were commercially available, reagent grade, and used as
purchased without further purification. Caution! Although no problems were
encountered in this work, perchlorate salts containing organic ligands are
potentially explosive. Only a small amount of the material should be prepared and
it should be handled with care. Yield: 330 mg (66.8%, based on Ni(II) salt). Anal.
Calcd. (%) for C44H36N4Ni2NaO12Cl: C, 53.46; H, 3.67; N, 5.67. Found: C, 53.4; H,
3.7; N, 5.7. UV–Vis, λmax (nm), (εmax (dm3 mol−1 cm−1)) (DMF), 486 (1293),
Magnetic moment diamagnetic.
The isolation and crystal structure determination of the trinuclear
compound, [(NiL)Na(NiL)]ClO4, unambiguously show for the first
[29] Single crystals having suitable dimensions for compound 1 were used for data
collection using a ‘Bruker SMART APEX II’ diffractometer equipped with graphite-