838
A. Karmakar et al. / Inorganic Chemistry Communications 9 (2006) 836–838
(c) D. Volkmer, A. Horstmann, K. Griesar, W. Haase, B. Krebs,
Inorg. Chem. 35 (1996) 1132–1135.
[4] (a) J. Catterick, P. Thornton, J. Chem. Soc., Dalton Trans. (1975) 233–
238;
than the free benzoic acid, which are 4.20 at 25 °C. Thus,
the catalysis presumably occurs due to the acidic nature
of the complex. It is also interesting to note that we could
use this catalyst for acetylation of ketals of glycerol without
hydrolyzing the ketal group (refer to supplementary table),
this adds further advantage to the catalytic process as the
ketals are generally susceptible towards strong acids. The
catalytic activity is ascertained by carrying out control
experiment in the presence and absence of 1 under identical
condition. By using catalytic amounts of complex 2, 3 inde-
pendently, no significant esterification reactions were
observed.
In conclusion we have demonstrated here a unique acid
included dimeric nickel complex which in turn is a catalyst
for esterification reactions and the composition of nickel
benzoate complexes having pyridine as additional ligand
is decided by the substituents attached on the benzoate.
(b) V.M. Novotortsev, Y.V. Rakitin, A.A. Pasynskii, V.T. Kalinnikov,
Doklady Akad. Nauk SSSR 240 (1978) 355–357;
(c) Q.-L. Wang, L.-H. Yu, D.-Z. Liao, S.-P. Yan, Z.-H. Jiang, P.
Cheng, Helv. Chim. Acta 86 (2003) 2441–2451;
(d) D. Volkmer, A. Hoerstmann, K. Griesar, W. Haase, B. Krebs,
Inorg. Chem. 35 (1996) 1132–1135.
[5] A mixture of benzoic acid (0.733 g, 6 mmol), potassium hydroxide
(0.337 g, 6 mmol) and anhydrous nickel chloride (3 mmol, 0.39 g) were
mixed together in a pastel and mortar and the mixture was heated to
100 °C for 15 min. The mixture was transferred into a round bottom
flask and toluene was added to the mixture (20 ml). To the heteroge-
neous mixture pyridine (0.47 g, 6 mmol) was added. The green solution
turned blue and the residue was filtered and discarded. The solution on
standing gave blue crystals of 1 in 20% yield. IR (KBr, cmꢂ1) 3432(wb),
3062(ms), 1711(m), 1613(s), 1567(s), 1537(s), 1398(s), 1224(w), 1160(w),
1070(w), 824(m). Visible (methanol) kmax 653 nm (14.05 Mꢂ1 cmꢂ1).
Crystal parameters of 1: C62H56N4O11Ni2, 1150.53, Monoclinic, P2(1)/
˚
˚
˚
c, a = 10.5022(1) A, b = 26.0953(4) A, c = 21.1012(3) A, a = 90°,
Acknowledgement
3
˚
b = 95.6010(10)°, c = 90°, Z = 4, V = 5755.34(13) A , qcalcd = 1.438
Mg mꢂ3, l (MoKa) = 0.720 mmꢂ1, Goof = 0.983, Final R1 = 0.0717.
[6] (a) E. Jabri, M.B. Carr, R.P. Hausinger, P.A. Karplus, Science 268
(1995) 998–1004;
The authors thanks DST(India) for financial support.
Appendix A. Supplementary data
(b) M.A. Pearson, L.O. Michael, R.P. Hausinger, P.A. Karplus,
Biochemistry 36 (1997) 8164–8172.
[7] The compound 2 was prepared by following procedure: o-nitro-
benzoic acid (0.084 g, 0.5 mmol) was dissolved in methanol (7 ml)
and to this a solution of nickel(II)acetate tetrahydrate (0.063 g,
0.25 mmol) was added dropwise. After the addition was complete,
the reaction mixture was stirred for 1 min and pyridine (59 mg,
0.75 mmol) was added. The blue colour got intensified and blue
needle like crystals appeared after 10 days. Yield 65%. IR(KBr,
cmꢂ1) 3437(bs), 2955(bs), 1650(s), 1562(s), 1537(s), 1404(s), 1363(s),
825(m), 753(m), 702(s), 661(m). Visible (methanol) kmax 658 nm
(9.0 Mꢂ1 cmꢂ1). A similar procedure gave 3 in 80% yield. IR(KBr,
cmꢂ1) 3314(bs), 3068(bs), 1562(s), 1562(s), 1521(s), 1450(m), 1347(s),
892(m), 815(s), 764(m), 712(s). Visible (methanol) kmax 667 nm
(6.7 Mꢂ1 cmꢂ1). Crystal parameters of 2: C29H25N5O9Ni, 646.25,
The CCDC deposition numbers for compound 1, 2 and
3 are 295858, 295859 and 297549. Table of catalytic ester-
ification reactions. Supplementary data associated with this
article can be found, in the online version, at doi:10.1016/
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˚
˚
Monoclinic
P2(1)/n,
˚
a = 8.5062(1) A,
b = 13.6451(9) A,
c = 15.2259(10) A, a = 90.00°, b = 98.5320(10)°, c = 90.00°, Z = 4,
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,
3
˚
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Goof = 1.013, Final R1 = 0.0626 Crystal parameters of 3:
˚
C
24H22N4O10Ni, 585.17, Monoclinic P2(1)/c, a = 14.4350(7) A,
˚
˚
b = 11.5135(6) A, c = 7.9153(4) A, a = 90.00°, b = 105.154(2)°,
3
(b) S.V. Kryatov, E.V. Rybak-Akimova, F. Meyer, H. Pritzkow Eur. J.
Inorg. Chem. (2003) 1581–1590;
˚
c = 90.00°, Z = 2, V = 1269.76(11) A ,
Goof = 1.069, Final R1 = 0.0757.
l ,
(MoKa) = 0.829 mmꢂ1