S. Basu et al. / Journal of Organometallic Chemistry 695 (2010) 2098e2104
2101
Scheme 2.
2.5.5. Synthesis of 6, 10, 12, 12-tetramethyl-11, 13-dioxa-5-aza-12-
stanna-dibenzo [a,e] cyclononene [Me2SnL3] (5)
Dark bottle green crystals of 5 were obtained from ethanol.
Yield: 55%; m.p.; 94e96 ꢁC. Anal. Calc. for C17H19NO2Sn: C, 52.62; H,
4.93; N, 3.60. Found: C, 52.13; H, 4.46; N, 3.29%. IR (KBr pellets,
cmꢀ1): 3056, 1597 (nC]N), 1521, 1462, 1433, 1326, 1284, 1182,
851 776, 750, 731 (nSneC), 565(nSneO), 524 (nSneN). 1H NMR (CDCl3,
dH): Ligand skeleton: 7.58 (d (8.0 Hz), 1H, H13); 7.30 (d (8.0 Hz), 1H,
H11), 7.16 (dd (7.4 Hz), 1H, H4), 7.08 (d (8.0 Hz), 1H, H2), 6.88 (d
(8.0 Hz), 1H, H5), 6.69 (dt, 2H, H3 and H12), 2.79 (s, 3H, H70), 2.18 (s,
Fig. 4. Molecular structure of Ph2SnL2 (4) at 35% probability level. Hydrogen atoms
have been omitted for clarity; the bond between C24eN1 could not be located as the
molecule is disordered.
3H, H100); Sn-Me (2J (119Sn-1H) ¼ 38.6 Hz): 0.60 (s, 6H), ppm. 13
C
NMR (CDCl3, dC): 177.20 [C9], 168.36 [C7], 160.71 [C1], 137.31 [C11],
134.01 [C13], 133.64 [C6], 130.90 [C3], 130.02 [C10], 125.00 [C2],
120.73 [C8], 119.95 [C12], 118.43 [C4], 117.49 [C5], 22.25 [C70] and
17.17 [C-100); Sn-Me (1J (119Sn-13C) ¼ 1272.2 Hz): ꢀ0.001 ppm. 119Sn
NMR (CDCl3) dSn: ꢀ137.63, ppm.
2.5.4. Synthesis of 6-methyl-12, 12-diphenyl-11, 13-dioxa-5-aza-
12-stanna-dibenzo [a, e]cyclononene [Ph2SnL2](4)
An identical method to that of 1 was followed to synthesize 4
using ortho-aminophenol, ortho-hydroxyacetophenone and
Ph2SnO in equimolar ratios. Green colored crystals was obtained
from an ethanol. Yield: 62%; m.p.: 206e208 ꢁC. Anal. Calc. for
C26H21NO2Sn: C, 62.68; H, 4.24; N, 2.81. Found: C, 62.26; H, 3.76; N,
2.35%. IR (KBr pellets, cmꢀ1): 3054, 1601, 1570 (nC]N), 1531, 1466,
1430, 1318, 1187, 847, 761, 733, 699, (nSneC), 523 (nSneO), 448 (nSneN).
1H NMR (CDCl3, dH): Ligand skeleton: 7.59 (d (8.0 Hz),1H, H13); 7.44
(t (7.6 Hz), 1H, H11), 7.17e7.00 (m, 2H, H4 and H2), 6.98 (d (8.0 Hz),
2H, H5 and H10), 6.73 (dd (7.0 Hz), 1H, H3), 6.62 (t (6.4 Hz), 1H,
H12), 2.77 (s, 3H, H70); Sn-Ph: 7.86 (m, 4H, H-2*) (3J(119/
2.5.6. Synthesis of 6, 10-dimethyl-12, 12-diphenyl-11, 13-dioxa-5-
aza-12-stanna-dibenzo [a,e] cyclononene [Ph2SnL3](6)
Bottle green colored crystals of compound 6 was obtained from
ethanol. Yield: 70%; m.p.; 138e140 ꢁC. Anal. Calc. for C27H23NO2Sn:
C, 63.31; H, 4.52; N, 3.60. Found: C, 62.97; H, 4.01; N, 3.22%. IR (KBr
pellets, cmꢀ1): 3049, 1587, 1572 (nC]N), 1529, 1466, 1429, 1286, 1191,
835, 745, 731, 698, (nSneC), 529 (nSneO), 451 (nSneN). 1H NMR (CDCl3,
dH): Ligand skeleton: 7.48 (d (8.0 Hz), 1H, H13); 7.17e7.06 (m, 3H,
H2, H4 and H11), 6.98 (d (8.0 Hz), 2H and H5), 6.65 (dd (7.2 Hz), 2H,
H3 and H12), 2.77 (s, 3H, H70), 2.47 (s, 3H, H100); Sn-Ph: 7.83e7.61
(m, 4H, H-2*) (3J(119/117Sn-1H) ¼ 46.8 Hz), 7.41e7.33 (m, 6H, H-3*
and H-4*), ppm. 13C NMR (CDCl3, dC): 176.13 [C9], 167.10 [C7], 159.10
[C1], 137.27 [C11], 132.12 [C13], 132.00 [C6], 129.50 [C3], 128.92
[C10], 123.47 [C2], 119.08 [C8], 118.63 [C12], 116.96 [C4], 116.06 [C5],
21.31 [C70] and 17.17 [C-100); Sn-Ph: 138.65 (C-1*) (J(119/
117Sn-13C) ¼ 959.8.0 Hz), 136.67 (C-2*) (2J(119/117Sn-13C) ¼ 56.2 Hz),
130.29 (C-4*) (3J(119/117Sn-13C) ¼ 16.7 Hz), 128.67 (C-3*) (4J(119/
117Sn-13C) ¼ 86.2 Hz), ppm. 119Sn NMR (CDCl3) dSn: ꢀ319.46, ppm.
117Sn-1H) ¼ 44.8 Hz), 7.40e7.32 (m, 6H, H-3* and H-4*), ppm. 13
C
NMR (CDCl3, dC): 175.79 [C9], 168.78 [C7], 159.08 [C1], 135.76 [C11],
131.97 [C13], 131.30 [C6], 130.66 [C3], 124.52 [C10], 123.54 [C2],
119.94 [C8], 118.71 [C12], 117.52 [C4],116.07 [C5], 21.00 [C70]; Sn-Ph:
138.47 (C-1*) (J(119/117Sn-13C) ¼ 958.0 Hz), 136.67 (C-2*) (2J(119/
117Sn-13C) ¼ 54.3 Hz), 129.63 (C-4*) (3J(119/117Sn-13C) ¼ 16.4 Hz),
128.64 (C-3*) (4J(119/117Sn-13C) ¼ 85.9 Hz), ppm. 119Sn NMR (CDCl3)
dSn: ꢀ320.40, ppm.
3. Results and discussion
N
N
3.1. Synthetic aspect
OH
R'
OH
The
2-(3-hydroxy-1-methyl-but-2-enylideneamino)-phenol
HO
HO
(H2L1) was prepared by condensing acetyl acetone with o-amino-
phenol in ethanol, whereas ligands H2L2 and H2L3 were obtained in
situ. The preparation of diorganotin(IV) complexes of type R2SnL
followed the procedure involving 1:1:1 stoichiometric addition of
ortho-aminophenol, diorganotin(IV) oxide (R2SnO; R ¼ Me or Ph),
and substituted ketones (acetyl acetone, 20-hydroxyacetophenone
or 2-hydroxy-3-methylacetophenone) to ethanol (see Schemes
1e3). The resulting mixture was maintained at reflux for 6 h to
give the products 1e6 in 50%e70% yield. The obtaining of 1 to 6
compounds in pure crystalline form was accomplished either by
slow evaporation of the reaction solvent reaching the precipitation
point or by crystallization done using suitable solvents. The
compounds were obtained as shiny green, non-hygroscopic, air-
stable crystalline solids. They are soluble in all common organic
(a)
(b)
(a) H2L1 (b) H2L2 (R' = H) and H2L3 (R' = CH3)
Ligands used in this study
7'
5
1
8
7
4
2
H2N
6
9'
EtOH, reflux
9
3
O
O
N
+
HO
OH
1*
-H2O
2*
HO
H2L1
Scheme 1.