22
D. Das et al. / Journal of Molecular Structure 842 (2007) 17–23
Et)2(NCS)2] (4b), C32H28N10SMn: calcd C, 57.23; H, 4.17;
N, 20.87. Found: C, 57.17; H, 4.22; N, 21.00%. [Mn(b-Nai-
Bz)2(NCS)2] (4c), C42H32N10SMn: calcd C, 63.40; H, 4.03;
N, 17.61. Found: C, 63.31; H, 4.10; N, 17.72%.
respectively. The structure was solved by direct method
using SHELXS-97 [22] and successive difference
Fourier syntheses. All non-hydrogen atoms were refined
anisotropically. The hydrogen atoms were fixed geomet-
rically and refined using riding model. In the final
difference Fourier map the reꢀsi3dual maxima and minima
˚
3.4. X-ray crystal structure determination of 3b and 4b
were 0.470ꢀ3and ꢀ0.252 e A
for 3b and 0.273 and
˚
ꢀ0.247 e A for 4b. All calculations were carried out
using SHELXL-97 [23], ORTEP-32 [24], and PLA-
TON-99 [25] programs.
A crystal suitable for X-ray analysis was mounted on the
Bruker SMART CCD area detector equipped with fine-fo-
cus sealed tube graphite monochromator and MoKa radi-
˚
ation (k = 0.71073 A). Data were collected at 296(2) K for
4. Conclusion
these complexes (Table 3). Red coloured blocked crystal
size were 0.2 · 0.2 · 0.1 mm for 3b and 0.3 · 0.2 · 0.2 mm
for 4b. Unit cell parameters were determined from least-
squares refinement of setting angles with 2h range 3.8–
56.7ꢁ for 3b and 3.84–56.6ꢁ for 4b. The hkl range were
ꢀ25 6 h 6 13, ꢀ18 6 k 6 18, ꢀ16 6 l 6 17 for 3b and
ꢀ25 6 h 6 23, ꢀ15 6 k 6 18, ꢀ16 6 l 6 19 for 4b. A sum-
mary of the crystallographic data and structure refinement
parameters is given in Table 4. Of 10657 collected reflec-
tions 3781 unique reflection (I > 2r(I)) for 3b and of
10785 collected data 3914 unique data for 4b were recorded
using the x-scan technique. Data were corrected for Lor-
entz polarization effects and for linear decay. Semi-em-
pirical absorption correction based on w-scans were
applied. Data refinement and reduction were carried
out by Bruker SMART and Bruker SAINT programme,
We have synthesized Mn(II) complexes of 1-alkyl-2-
ꢀ
(naphthyl-b-azo)imidazoles with azide N3 or thiocyanate
(NCSꢀ) as counter ion. Ligand serves as bidentate unsym-
metric imidazole-N and azo-N chelator to synthesize high
spin distorted octahedral [Mn(b-NaiR0)2(X)2] (X ¼ N3
ꢀ
(3 and NCSꢀ (4); R0 = Me (a) and Et (b)). The complexes
are structurally characterized by single crystal X-ray dif-
fraction studies. The stereochemistry is also supported by
EPR spectra. Redox properties show high potential
Mn(III)/Mn(II) couple and azo reductions.
5. Supplementary data
Crystallographic data for the structural analysis are in
the Cambridge Crystallographic Data Centre, and CCDC
No. 602420 for [Mn(b-NaiEt)2(N3)2] (3b) and 601287 for
[Mn(b-NaiEt)2(NCS)2] (4b). Copies of this information
may be obtained free of charge from the Director, CCDC,
12 Union Road, Cambridge, CB2 1FZ, UK (email:depos-
Table 3
Crystallographic data of [Mn(b-NaiEt)2(N3)2] (3b) and [Mn(b-Nai-
Et)2(NCS)2] (4b)
[Mn(b-NaiEt)2(N3)2]
(3b)
[Mn(b-NaiEt)2(NCS)2]
(4b)
Acknowledgement
Empirical formula
Formula weight
Temperature (K)
Crystal system
C
639.60
296(2)
Monoclinic
C2/c
30H28N14Mn
C32H28N10S2Mn
671.70
296(2)
Monoclinic
C2/c
Financial support from Department of Science and
Technology, New Delhi is gratefully acknowledged.
Space group
Crystal size (mm)
Unit cell dimensions
a (A)
0.20 · 0.20 · 0.10
0.30 · 0.20 · 0.20
References
˚
19.2755(15)
13.9617(11)
13.4542(10)
123.2430(10)
3028.2(4)
8
0.71073
0.483
1.403
19.8815(16)
13.9714(11)
14.2612(11)
125.3960(10)
3229.2(4)
8
0.71073
0.578
1.382
˚
b (A)
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˚
c (A)
b (ꢁ)
3
˚
V (A)
Z
˚
k (A)
l (Mo-Ka) (mmꢀ1
)
Dcalcd (mg mꢀ3
)
Refine parameters
Total reflections
Observed data [I > 2r 3761
204
10657
204
10785
3914
(I)]
a
R1 [I > 2r (I)]
wR2
0.0431
0.1118
0.849
0.0556
0.1383
0.882
b
Goodness of fit
a
R = RjF0 ꢀ Fcj/RF0.
1=2
2
b
wR2 ¼ ½RwðF 20 ꢀ F c2Þ=RwF 40ꢃ
,
w = 1/[r2 (F 2oÞ þ ð0:0635PÞ ꢃ (3b);
2
w = 1/[r2 ðF o2Þ þ ð0:7000PÞ ꢃ (4b) where P ¼ ðF o2 þ 2F 2cÞ=3.
[10] E.C. Constable, Coord. Chem. Rev. 93 (1989) 205.