A. Mustapha et al. / Polyhedron 30 (2011) 1530–1537
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evaporation of the mother liquor. Yield 67%. Anal. Calc. for
54H66N10O12Cu4 2MeOH: C, 49.26; H, 5.46; N, 10.26. Found: C,
49.21; H, 5.32; N, 10.54%. FTIR [(
/cmꢀ1 (KBr)]: 2925, 1634, 1562,
2.7.1. Reactions of [(H2L)Cu]+ with nickel halides
C
This reaction was carried as described above on a 0.5 mmol
scale. The products obtained from the reaction was consistent with
[(H2L)Cu]+ [7]. The parent ion (m/z 521) of [(H2L)Ni]+ is a dominant
feature of the mass spectrum of the reaction solution indicative of
some metal exchange.
m
1408, 1383, 1276, 1020, 871, 753. Mass spec. (ESI) m/z 526
(100%, LCu+). kmax (solid reflectance) 670 nm.
2.4. Preparation of [{(L)Zn}ZnCl]
2.7.2. Reactions of [(H2L)Zn]+ with nickel or copper halides
These reactions were carried as described above on a 0.5 mmol
scale. The products obtained were consistent with [(H2L)Ni]+ and
[H2L)Cu]+, respectively [7].
H3L (0.1 g, 0.22 mmol) was dissolved in methanol (15 ml), to
which was added Zn(NO3)2ꢁ6H2O (0.06 g, 0.22 mmol). The mixture
was stirred at 50 °C for 5 min, followed by addition of two drops of
triethylamine. A methanolic (5 ml) solution of ZnCl2 (0.03 g,
0.22 mmol) was added to the mixture drop-wise to obtain a
brownish solution. This was allowed to cool and filtered. Crystals
were grown by the slow evaporation of the mother liquor. Yield
47%. Anal. Calc. for C27H33N4O3Zn2ClꢁMeOHꢁ3H2O: C, 47.11; H,
2.8. Preparation of [(HL)Fe]NO3
H3L (0.13 g, 0.28 mmol) was dissolved in methanol (30 ml) fol-
lowed by addition of Fe(NO3)3ꢁ9H2O (0.11 g, 0.28 mmol). To the
brown mixture three drops of KOH solution (in methanol) was
added, the mixture was refluxed for 1 h, allowed to cool and
filtered. Crystals were grown directly from the mother liquors by
vapour diffusion with diethyl-ether. Although the crystals were
subjected to crystallographic analysis the data obtained failed to
refine to a satisfactory solution (see Supplementary material).
Crystal data: [(HL)Fe], orthorhombic Pc21a, a = 21.7392(18) Å,
b = 7.2251(4) Å, c = 38.0527(31) Å, V = 5979.61(8) Å3. Anal. Calc.
for C27H34N5O6Fe: C, 56.01; H, 5.90; N, 11.61. Found: C, 56.01; H,
6.07; N, 7.85. Found: C, 47.25; H, 5.15; N, 8.12%. FTIR [(m
/cmꢀ1
(KBr)]: 3426, 2934, 1485, 1275, 763. Mass spec. (ESI) m/z 527
(100%, LZn+), 593 (20%, LZn2+).
2.5. Preparation of [{(HL)Ni}CuCl2]
H3L (0.1 g, 0.22 mmol) was dissolved in methanol (15 ml), to
which was added Ni(NO3)2ꢁ6H2O (0.06 g, 0.22 mmol). The mixture
was stirred at 50 °C for 5 min, followed by the addition of two
5.90; N, 12.06%. FTIR [(m
/cmꢀ1 (KBr)]: 1475, 1265, 1388,, 615. Mass
drops triethylamine.
A methanolic solution (5 ml) of CuBr2
spec. (ESI) m/z 518 (100%, LFe+); 1090 (29%, KL2Fe3+). kmax (solid
(0.05 g, 0.22 mmol) was added dropwise to the mixture. The solu-
tion changed colour immediately from purple to brown. The solu-
tion was allowed to cool and filtered to produce a brown powder
which was recrystallised from nitromethane. Yield 68%. Anal. Calc.
for C27H34N4Cl2Cu1O3Ni1ꢁMeNO2: C, 46.92; H, 5.20; N, 9.77. Found:
reflectance) 475 nm.
3. Results and discussion
C, 46.44; H, 5.05; N, 9.17%. FTIR [(m
/cmꢀ1 (KBr)]: 2925, 1610, 1480,
The multidentate ligand systems H3L can be prepared with ease
by hydrogenating the Schiff base species generated from the tris
(2-aminoethyl)amine and salicylaldehyde [8]. Treatment of H3L
in situ with three equivalents of nickel acetate produced an off-
white material. It is notable that the parent [(H2L)Ni]+ has a prom-
inent band in the near infra-red (950 nm) which is absent in this
product. Recrystallisation revealed the complex to be dimetallic;
namely [{(HL)Ni}Ni(OAc)2] (Fig. 3). The internalised nickel is coor-
dinated by an N4O2 motif in a similar manner to [(H2L)Ni]+ [6].
However, the additional pendant phenoxide is not deprotonated
and consequently the metallo-ligand does not carry a negative
charge. Nickel acetate chelates to the phenolates (O1, O2) which
1390, 760. Mass spec. (ESI) m/z 521 (100%, LNi+). The parent ion
(m/z 526) of [(H2L)Cu]+ is a prominent feature of the mass spec-
trum of the reaction solution indicative of some metal exchange.
kmax (solid reflectance) 480, 820.
2.6. Preparation of [{(HL)Ni}ZnBr2]
H3L (0.1 g, 0.22 mmol) was dissolved in methanol (15 ml), to
which was added Ni(NO3)2ꢁ6H2O (0.06 g, 0.22 mmol). The mixture
was stirred at 50 °C for 5 min, followed by the addition of two
drops of triethylamine, after which methanolic (5 ml) solution of
ZnBr2 (0.05 g, 0.22 mmol) was added drop-wise. The light purple
mixture was stirred for further 10 min, allowed to cool and filtered.
Crystals were obtained by slow evaporation of the saturated solu-
tion. Yield 72%. Anal. Calc. for C27H33N4O3Ni1Zn1Br2ꢁMeOH: C,
43.20; H, 4.80; N, 7.04. Found: C, 42.90; H, 5.01; N, 7.04%. FTIR
[(m
/cmꢀ1 (KBr)]: 3406, 2980, 1475, 1255, 758. Mass spec. (ESI) m/
z 521 (100%, LNi+). kmax (solid reflectance) 555, 950.
2.7. Preparation of [(H2L)Cu] Et3NH+ [ZnCl4]
H3L (0.23 g, 0.5 mmol) was dissolved in methanol (15 ml), fol-
lowed by addition of Cu(NO3)2ꢁ2.5H2O forming a green solution
of [(H2L)Cu]+. The solution was stirred at 50 °C for 5 min. Four
drops of triethylamine was added and the mixture stirred for a fur-
ther 2 min.
A methanolic (5 ml) solution of ZnCl2 (0.07 g,
0.05 mmol) was added drop-wise and the pale green mixture
allowed to cool. The solution was filtered and allowed to stand.
X-ray quality crystals were grown by slow evaporation of the
saturated solution. Yield 82%. Anal. Calc. for C33H51Cl4Cu1N5O3Zn1:
C, 42.78; H, 6.64; N, 7.56. Found: C, 42.77; H, 5.19; N, 7.69%. FTIR
Fig. 3. The X-ray crystal structure of [{(HL)Ni}Ni(OAc)2]. The metrical parameters of
the [(H2L)Ni] moiety are given in Table 2. The thermal ellipsoids are drawn at 50%
probability.
[(
m
/cmꢀ1 (KBr)]: 2980, 1603, 1480, 1265, 765. Mass spec. (ESI)
m/z 526 (100%, LCu+).