1292
Sandya Rani, B. Ramachandra Bhat / Inorganic Chemistry Communications 13 (2010) 1289–1292
[11] D. Ramakrishna, B. Ramachandra Bhat, R. Karvembu, Catal. Commun. 11 (2010)
498.
[12] N. Deligonul, M. Tume, Transit. Metal Chem. 31 (2006) 920.
[13] G.N. Rao, C. Janardhana, K. Pasupathy, P.M. Kumar, Ind. J. Chem. 39 (2000) 151.
[14] F. Tisato, F. Refosco, U. Mazzi, G. Bandoli, M. Nicolini, J. Chem. Soc. Dalton Trans.
(1987) 1693.
[15] L.D. Albin, M. Jacobson, D.B. Olson, US Patent 5426,085, 1995.
[16] FeL1: yield: 57%; CHNS found (calc.) for C49H39ClNOSP2Fe, C: 69.69(69.80), H: 4.60
(4.66), N: 1.60(1.66), S: 3.69(3.80); IR (KBr, cm−1): 1599, 1439, 1306, 1078, 757,
693, 543, 420. UV–vis: λmax (nm) 248, 294, and 381. μeff: 6.05 B.M. FeL2: yield:
60%. CHNS found (calc.) for C49H38Cl2NOSP2Fe, C: 63.61(63.83), H: 4.115(4.15), N:
1.49(1.52), S: 3.39(3.48); IR (KBr, cm−1): 1599, 1440, 1320, 1087, 752, 692, 542,
428. UV–vis: λmax (nm) 247, 288, 388. μeff: 5.92 B.M. FeL3: yield: 52%. CHNS
found (calc.) for C49H38BrClNOP2SFe, C: 67.00(67.06), H: 4.29(4.36), N: 1.55(1.60),
S: 3.59(3.65); IR (KBr, cm−1):1597, 1434, 1315, 1084, 758, 696, 540, 498. UV–vis:
λmax (nm) 248, 294, 390. μeff: 5.96 B.M. FeL4: yield: 56%. CHNS found (calc.) for
out [31] (Table 4). The catalytic activity varies with the substituent on
the Schiff base ligand. It was observed that the activity decreased with
an increase in the bulkiness of the substituents.
A substrate to catalyst ratio was varied to determine the effect of
concentration of catalyst with respect to substrate. A 0.04 mmol of
catalyst was sufficient for the effective transformation of benzyl
alcohol to benzaldehyde (Table 3, entry 5). The reaction was also
studied in the absence of a catalyst. The yield was insignificant in this
case (Table 3, entry 1). This observation reveals the catalytic role of Fe
(III) complexes. The reaction was studied at various substrates to
oxidant ratios (Table 3). A minimum quantity of 0.75 mmol of the
oxidant was sufficient for the effective oxidation of benzyl alcohol to
benzaldehyde (Table 3, entry 10).
The oxidation was extended to a variety of alcohols including
primary and secondary, aromatic, aliphatic and cyclic alcohols. All the
synthesized Fe(III) complexes were found to catalyze the oxidation of
alcohols to corresponding carbonyl compounds in good yield
(Table 4). All the benzylic primary and secondary alcohols studied
were oxidized smoothly to give aldehydes and ketones respectively.
Among the various alcohols studied those containing aromatic
substituent were found to be more reactive than alicyclic and
aliphatic alcohols. Furthermore, cyclohexanol was oxidized relatively
better than the linear aliphatic alcohols. All the reactions occurred
with complete selectivity for ketones or aldehydes and no other
products were detected in the reaction mixture. The over oxidation to
carboxylic acid was ruled out by a derivative test.
C
49H38ClN2O3P2SFe, C: 66.20(66.26), H: 4.26(4.31), N: 3.10(3.15), S: 3.59(3.61); IR
(KBr, cm−1):1607, 1440, 1310, 1089, 757, 691, 541, 472. UV–vis: λmax (nm) 246,
288, 394. μeff: 5.82 B.M. FeL5: yield: 55%. CHNS found (calc.) for C53H41ClNOP2SFe,
C: 67.67(68.78), H: 4.72(4.73), N: 1.58(1.60), S: 3.60(3.67); IR (KBr, cm−1):1607,
1440, 1303, 1073, 752, 693, 541, 451. UV–vis: λmax (nm) 248, 288, 419. μeff: 6.00
B.M.
[17] C.A. Sureshan, P.K. Bhattacharya, J. Mol. Catal. A: Chem. 136 (1998) 285.
[18] V. Paredes Garc, R.O. Latorre, E. Spodine, Polyhedron 23 (2004) 1869.
[19] H. Aneetha, J. Padmaja, P.S. Zacharias, Polyhedron 15 (1996) 2445.
[20] S.A.A. Latif, H.B. Hassib, Y.M. Issa, Spectrochim. Acta A 67 (2007) 950.
[21] N. Deligonul, M. Tumer, Transit. Metal Chem. 31 (2006) 920.
[22] A.A. Solimana, W. Linert, Thermochim. Acta 338 (1999) 67.
[23] M.M. Tamizh, K. Mereiter, K. Kirchner, B. Ramachandra Bhat, R. Karvembu,
Polyhedron 28 (2009) 2157.
[24] M. Bagherzadeh, L. Tahsini, R. Latifi, V. Amani, A. Ellern, L. Keith Woo, Inorg. Chem.
Commun. 12 (2009) 476.
[25] N.T. Madhua, P.K. Radhakrishnan, M. Grunert, P. Weinberger, W. Linert,
Thermochim. Acta 407 (2003) 73.
[26] J. Sanmartın, A.M. Garcıa Deibe, M. Fondo, D. Navarro, M.R. Bermejo, Polyhedron
23 (2004) 963.
[27] S.A. Sallam, A.S.O. Basheir, A. El-Shetary, A. Lentz, Transit. Metal Chem. 27 (2002)
447.
[28] S.A. AbouEl-Enein, F.A. El-Saied, T.I. Kasher, A.H. El-Wardany, Spectrochim. Acta A
67 (2007) 737.
[29] J.B. Luiz, F.M. Andrade, E.L. Sa, G.R. Friedermann, A.S. Mangrich, J.E. Barclay, D.J.
Evans, T. Hasegawa, F.S. Nunes, J. Br. Chem. Soc. 15 (2004) 10.
[30] The reaction product analysis was carried out using gas chromatography (GC)
(Shimadzu 2014, Japan); the instrument has a 5% diphenyl and 95% dimethyl
siloxane Restek capillary column (30 m length and 0.25 mm diameter) and a
flame ionization detector (FID). The initial column temperature was increased
from 60 °C to 150 °C at the rate of 10 °C/min and then to 220 °C at the rate of
40 °C/min. Nitrogen gas was used as the carrier gas. The temperatures of the
injection port and FID were kept constant at 150 °C and 250 °C, respectively
during product analysis. The retention times for different compounds were
determined by injecting commercially available compounds under identical gas
chromatography conditions. The oxidation products are commercially available,
and were identified by GC co-injection with authentic samples.
[31] A solution of iron(III) complex (0.04 mmol) in acetonitrile was added to the
solution of substrate (1 mmol) and H5IO6 (1 mmol). The mixture was refluxed for
90 min. At the requisite times aliquots of the reaction mixture were removed and
the alcohol and aldehyde/ketone extracted with ether. The ether solution was
then analyzed by GC using dichlorobenzene as the internal standard.
In conclusion, the octahedral, high spin Fe(III) triphenylphosphine
complexes (FeL1–FeL5) containing N-(2-mercaptophenyl)salicylide-
neimine, its derivatives/ N-(2-mercaptophenyl)naphthylideneimine
have proved to be an efficient catalyst in the oxidation of primary and
secondary alcohols to carbonyl compounds in the acetonitrile–
periodic acid system. The small reaction time and good conversion
makes this system useful in synthetic organic chemistry.
References
[1] E. Ispir, Dyes Pigments 82 (2009) 13.
[2] M.H. Fonseca, E. Eibler, M. Zabel, B. Konig, Inorg. Chim. Acta 352 (2003) 136.
[3] L. Xub, M.L. Trudella, Tetrahedron Lett. 44 (2003) 2553.
[4] J.M. War, Tetrahedron Lett. 27 (1986) 3139.
[5] N. Sathya, A. Manimaran, G. Raja, P. Muthusamy, K. Deivasigamani, C.
Jayabalakrishnan, Transit. Metal Chem. 34 (2009) 7.
[6] R. Ramesh, Inorg. Chem. Commun. 7 (2004) 274.
[7] S. Kannan, R. Ramesh, Polyhedron 25 (2006) 3095.
[8] S.J.S. Kalra, T. Punniyamurthy, J. Iqbal, Tetrahedron Lett. 35 (1994) 4847.
[9] D. Ramakrishna, B. Ramachandra Bhat, Inorg. Chem. Commun. 13 (2010) 195.
[10] M. Rong, C. Liu, J. Han, W. Sheng, Y. Zhang, H. Wang, Catal. Lett. 125 (2008) 52.