Crystal structure of tetrakis (imidazole) copper(ll) bromide (CuBr2

Indian Journ al of Pure & Applied Physics
Vol. 4 1. May 2003, pp. 350-353
Crystal structure of tetrakis (imidazole) copper(ll)
bromide (CuBr2 C 12 Ns Hu)
Pratyush Purkayastha, B K Sanna & AN Talukdar
Department of Physics. Gauhati University, Guwahati , Assam 78 1 014
Received 20 December 2002; accepted 14 March 2003
The crystal and molecular structure of tetrakis imidazole copper (II ) bromide (C uBr2C 12 NxH12 ) has heen in vesti gated
from three-dimensional intensity data. The two imidazole rings bonded to the central Cu atom throu gh the respective N
atom. which constitutes one-half of the asymmetric unit of the centrosymmetric structure under consideration . The distance
between Cu-Br- ion is found to be 3.376{1)A which excludes the possibility of formation of any covalent bond between
them.
[Keywords: Crystal structure, Tetrakis imidazole copper bromide, Biological membrane. Biopolymer)
1 Introduction
2 Experimental Details
The determination of crystal structure has been
considered owing to the presence of th e imidazole
en tity in the variety of biologically important
substances, notably as part of the a mino acid
hi stidine
and
metabolites
like
histamine u .
Involvement of imidazolium cations is even
implicated in proton translocation in biological
membranes 1 and also in electrostatic interactions in
biopolymers 4 . In addition, mixed ligand imidazole
copper(II) complexes have been shown to exhibit
antitumour',
superoxide
dismutase6·7
and
catecholase activiti.The structural formu la of the
compound (I) is as follows:
++
The crystals of tetraki s (im idazo le) copper(II)
bromide were grown by the reaction of CuO.nH 20
and imidazole with the add ition of co ncentrated
HBr. The slow evaporation of the resulting solution
yields the crystal of [Cu(Hlm) 4 Br:] where Him
means imidazole.
Pre limin ary
oscillation
and
Weissenberg
photographs indicated a triclinic crystal system with
no systematic absences consistent with the space
group P I . Table I shows the experimental data .
The unit cell parameters were refined by the leastsquare refinement method on the basi s of 25 hi gh
angle reflections with the setting angles lying in the
range 10 °~ 8 ~ 20°. Data were recorded up to 75 ° in
28 by the (J}-28 scan technique. The inte nsities were
corrected for the Lorentz and polarization factors
and also for absorption.
3 Structure Solution and Refinement
.2Br
(I )
The structure was solved by Patterson methods
using the program SHELXS-93 ~. The structure
refinement based on F was carried out usi ng the
program SHELXL-93 111 • Full matrix least squares
refinement, first with isotropic and the n with
anisotropic thermal parameters were carri ed out.
The Cu atom sits on special position (0.5, 0.5 , 0.0)
with occupancy of 0.5. All the hydrogen atoms we re
generated, using ridin g mode l and the ir positional
PURKAYASTHA et a/.: CRYSTAL STRUCTURE OF CuBr 2C 12 NxH 12
and the rmal parame te rs were refined . The fin al
agreeme nt res idu a l arrived at R = 0 .0600 for 3202
refl ecti ons wi th F > 4cr (F.,) and wR = 0 . 1733. The
fun cti on was minimized with we ight w =I I [sigma'
(F 112) + (0 . 141 4 * Pf + I .64* P] where P =[ M ax
(F112 , 0 )+ 2* Fc 2 ] /3 .
T he fin a l d iffe rence Fouri e r map showed peaks
lyin g in the range from 0 .70 to -0.6 1 eA·-' . Th e
atomi c scattering facto rs used were taken from the
In tern ati ona l T abl es fo r X-ray crysta llograph y.
Th e molecul ar geo metry calculati ons for the
present structure were carried out , usin g th e
program PARST 11 • The fin a l fracti ona l atomi c
coordin ates and equi va le nt isotropi c the rmal
para mete rs for a ll non-hydrogen ato ms are given in
Tab le 2 .
T ab le I -
Exr eri ment::t l data
Mo lecu lar formula
M olecul ar weight (M ,.)
C ry~ t a l sy stem
Space group
CuBr 2C 12 N xH 12
49 1.4
Tric lin ic
Un it ce ll di mensions
h = 8.650( I lA
c = I H >37(5lA
a= 95 .938 (2) 0
~ = I 04. 162(W
y = 117.090(4) 0
V olume
a = 8.640( I lA
z
2
Ca lcul ated densi ty D ,
Radiati on
Wave length
Absorptio n cocfficielll
F t 000)
Tempera ture
Goodness-of- ti t ·s·
1.9 11 M g/ m'
Cu-Ku
1.54 18 A
7.38 mm- 1
478
293( 2) K
0.966
0. 0600
0. 70 eA-'
-0 .6 1 eA- 3
0.059
/?
I'.Pmax.
!!J.plllltl.
( t. I
cr l "'·"·
35 1
pl anes through the ato ms of th e imidazole rin gs , it is
seen that, the maximum dev iati o ns of th e ato ms of
both the rings li e in the ran ge from -0 .009(9)A to +
0 .009 ( 12)A. The centra l Cu ato m dev iates fro m the
first imidazole mean plane [N 1-C I-N2-C2-C3]
onl y by -0.002(l )A and that fro m the seco nd mean
plane [N3-C4-N4-C5-C6] is 0 .030( I )A. Thi s
shows th at the two imid azo le ring pl anes are pl anar
individua ll y.
A ll the fiv e e ndocyc lic bo nd length s and bond
ang les of the imidazo le rin gs of the present structure
are a lmo st normal. The ave rage va lues fo r C = C , C
= N and C-C are 1.375 ( 15)A, 1.3 17( 15 )A and
1.366( 18)A, respecti ve ly. Th ese va lues are in good
agree ment with the corresponding va lues in the
structure
of
I -trity l-4-nitroimidazo le 1 \
transbi s-(imid azo le-N 3)
bis(cyanaimid onitro-N:O)
coppe r(II) 14 , cantena-po ly [[tetraki s( imid azo le-N-')co ppe r(Il)]-J..l-( di c hro mato-0 :0 ') ] 1\
imidazo le-4acetic ac id mono hydrate 11' a nd o th e r vari ous
imidazo le de ri vatives 15· 17- 211 •
PI
T able 2 Fractio nal ato mi c coordin ates and equ ivalent
isotropi c th ermal parameters (A 2 ) for non -hydrogen atoms with
esd ' s i n parentheses
A to1h
654 35(3l
A'
4 Res ults and Discussion
ORT EP 12
~ b ow in g
the
T he
di agra m
co nfo rmati o n of the mo lec ul es a nd rh e ato m
nu mbe rin g scheme w ith th erma l e llipsoi ds is g ive n
in Fig . I.
T he re are two im idazo le rin gs bonded to the
ce nt ral C u ato m of the mo lecu le unde r
conside rat ion. From the analysi . of the least squares
Cu i
Br l
Nl
N2
NJ
4
Cl
C2
C3
C4
C5
C6
X
y
7
0.5000(0)
0. 1349 ( 1)
0 578 8( 12)
0.5H65 ( 19)
0.6595( I I )
0 757 1( 1H)
0.4871 ( 16)
0.7370( 12)
0. 7 182( 18)
0.6270( 17)
0 8785 ( 13)
0.8 149( I 7)
0.5000(0)
0.35H I ( I )
0.75 52(9 )
1.0041 ( 13 )
0.4975(9)
0.4927( 14)
0.82 13( 13)
1.0457( 10)
0.8872( 15)
0.4955( 12)
0.4895( I I )
0.495 1( 13)
0.0000( 0 )
0.0854( I )
0.0590(5)
0. 135 0(9)
0. 1323(5)
0. 2994(8)
0. 1050(H)
0 I OSl:\( 7)
0.0579(9)
0.2264(7)
0 249X(7)
0. 1499(8)
* U eq
U,-q
I
.. * *
= :(Ii I .I· u IJl.J
(l. (/
0.05 36(7)
0.0436(4)
0 0393( 16)
0.0696(29)
0. 0398( 16)
0 0707(30 )
005 14(24)
0.0379( 18)
0.0532(26)
0 0497(23)
0 04 14( 19)
0 05 24(2 4)
·(/ · {/ .
l .J
In the ana lys is, it has been o bserved that, the
C u(JI) atom sits o n a spec ial pos iti o n (0 .5 . 0 .5, 0.0)
with th e occupanc y o f 0 .5 and are linked to two
imidazo le nitrogen ato ms in o ne-h a lf of the
asy mmetric un it [va lu es fo r C u-N I and C u- N2 are
1.995(8)A and I .996(8)A, respec ti ve ly] sh owin g
perfect square p lanar co nfi gurati o n. T hus, th e
coordi natio n sph e re of th e C u(ll) ato m is in a sq uare
planar arran geme nt. T he N ato ms of the im idazo le
352
INDIAN J PURE & APPL PHYS , VOL 4 1, MAY 2003
li gand and the Cu(II) atom are a lmost copl a nar. The
Cu-N dista nces and N- Cu-N ang les [90 .2(3t]
agree we ll wi th the corresponding mean geo metry
in othe r Cu(II) compl exes wi th unide ntate or
bide ntate N-donor li gands 2 1·D a nd al so other related
structures 1' · 17 • 1x.
0
th e dihedral ang le betwee n the planes defin ed by the
atoms N I to C3 and N3 to C6 be ing 90. 9( 4
t.
~
Brl
Fig. 2 - Packi ng o r the molec ul es in the unit cell as viewed
down th e c-axis
Fig. I - Mo lecu lar stru cture or the titl e co mpo und showing the
atomic numbering scheme (Displacement ellipsoid s are dra wn
at th e 50 % probab ilit y level and H ato ms are shown as small
cin.: les or an arbitrary radiu s)
The Br- ion does not form any cova lent bond .
The distance be tween Cu-Br- ion is found to be
3.376( I )A whic h exc ludes the possibility of
formation of any cova le nt bond be tween the m. An
inspecti on of the mo lecul ar geo me try revealed th at,
th e re are short contacts between the two Br- ions
with the two aromatic hydrogen atoms and thu s the
mol ec ul e stabili zes in the crysta lline space. It has
bee n observed that, both th e imidazole rings are
a lmost planar and are perpendicular to each other,
From the study of the tors ion ang les about
various bonds in the present structure, it is found
that, th e dev iati ons from pl ana rity are ve ry sma ll.
The va lue of th e torsion ang les o f both the
imidazole rin gs a re nea rl y the sa me, i.e. it vari es
from -2.3( I ) 0 to 3.2( I ) 0 in the ring
I- C3 and 3. 1(2t to 1.5( It in the ring N3- C6. T he sa me type
of vari at ion of torsion ang les is a lso found in the
of
N,N '-bi s( l -methyli midazo le-2y lstru cture
methyl )- l ,3-diaminopropane-2-oF 4 and 1-benzy l-2(2,6-dichloroani linomethyl )- 1H-be nzimidazo le 25 .
The torsion angles N 1-Cu I-N3-C4 = 72 .9(9) 0
and NI-Cui-N3- C6 = -108 .1 (9t , as also th e
torsion ang les N3-Cu 1- N I-C3=85 .2( It a nd N3 Cu 1- N 1-C I = -97 .7(9t bea r ev ide nce that , th e two
imi dazo le rin g planes are tra nsve rse to eac h othe r.
The pack in g diagram of the mo lec ul es in the
c rys ta lline space as viewed down the c-ax is o f the
unit ce ll is depicted in Fig. 2. There is no intra or
intermol ecular
hydrogen
bond
tn
the
centrosy mmetri c structure but, there ex ist short
con tacts less than 3A between the Br- ion a nd the
PURKA YASTHA et al.: CRYSTAL STRUCTURE OF CuBr2C 12NxH12
two aromatic hydrogen atoms. Th e detail s of the
sho rt contact geometry are as follows :
Br ---- C2ci> 3.370(9)A , Br ---- H2<i> 2.543( I O)A
and Br ---- H2ci> - C2<i> 148 .9(9) 0 [Symmetry code (i)
x + I , y + I , z] and Br ---- C3<ii> 3 .573( 17)A, Br ---H3<ii> 2.786(16)A and Br ----H3<ii) - C2cii> 143 .0( 1) 0
[Symmetry code (i i) -x+ I , -y+ I , -z].
It is to be noted th at, the two Br----C di stances
3.370(9)A and 3.573( 17)A of the present structure
are intermediate values and can be compared with
th ose observed in several imidazole structures 26 .
5 Acknowledgement
The authors thank Dr C R Bhattacharj ee,
Department of Chemistry, Assam University ,
Silchar, for suppl yin g the c rysta l sample and
De partment of Biophys ics, All Indi a In stitute of
Medical Sciences, New De lhi, for diffractome te r
data collection.
References
Kurd ziel K . Glowiak T & Jezierska J, J Chem Soc, Dalton
Trans, (2000) I 095.
2
M endoza-Di az G, Driessen W L & Reed ijk J, Acta Cryst,
C52 ( 1996) 960.
3
Zundel G & Widemann E G, Proc First Eur Biophysics
Cong,re.u, Vienna, ( 197 1) 43.
4
Reinert K E, Pruc XXIII/nt em ationai/ UPAC
Boston. (1971) 1249.
5
Tamura H. l mai H, Huwahara J & Sguira Y , J Am Chem
Sue . I 09 ( 1987) 6870.
6
Bhirud R G & Srivas tava T S, ln org Chim Acta , 173
( 1990) 12 1.
7
Bienvenue E. Chona S, Lobo-Recio M A, Marzin C,
Pacheco P, Seta P & T arrago G, J lnorg Biuchem, 57
( 1995) 157.
8
C01~{eren ce,
Abu hijlch A L , Woods C, Bogas E & L eGuenniou G,
353
lnorg Chim Acta, 67 ( 1992) 195.
9
Sheldriek G M , SHEU(S93, Program for th e so!uti011 of
crystal structures, (U niversity of Gottingen, Germany).
1993.
10
Sheldrick G M , SHELXL97, Program fur th e re.finement of
Clystal structures, (U niversity of Gottingen, Germany).
1993.
II
Nardelli M , Cumput Che111 , 7 ( 1983) 95.
12 Joh nson C K , ORTEP/1, Report ORNL - 5 138. Oak Ri dge
National Laboratory, Tennessee, USA, 1976.
13
Skrzypczak-Jankun E & Ku rumbai l G, Acta Crvst , C52
( 1996) 189.
14
Kozi sek J, Diaz J G. Hvastijova M & Jager L , Acta Cn·st.
C53 ( 1997) 703.
15 Pan L , Zhen g N, Zhou X. Wu Y, Wu Q & Jin X. Acta
Cryst, C54 ( 1998) 1802.
16
Okabe N & Hayashi T, Acta Cryst, C55 ( 1999) I 142.
17
Bohen F M , Goddard R. Mindis A B E. Alexakis A &
Pfaltz A, Acta Cryst , C53 ( 1997) 11 42.
Us
Bhadbhade M M & Sures h E, Acta Crrst. C53 ( 1997) 422.
19
Zhang C, Sun J, Kong X & Z hao C, Acta Clyst, C55
( 1999) 873.
20
Kubi ck i M , Borowick T, Suwinski J & Wagner P, Acw
Cryst , C57 (200 I ) I 06.
2 1 Munno G D, Julve M , Nicolo F, Lloret F, Gaus J. Rui z R
& Sinn E, Angew Chem /111 Ed Eng /, 32 ( 1993) 61 3.
22
Su C C, Liu Y L , Liu S J & Chang T H, Polvh edron. 12
( 1993) 2687.
23
Allen F H & Kenn ard 0 , Chem Des A utom News, 8 ( 1993 )
31.
24
l vo V, Ademir
C54 ( 1998) 97 .
25
Engin K , Suheyla 0, M eral T & Haken G, Acta Crvst , C54
( 1998) 854.
26
Hensen K , Kettner M & Bo lte M , Acta Cn·st , C54 ( 199X )
13 12.
, Marceiela S & Yaldir R C. Acta Crrst.

Download Report