Identification code

Ni Complex 13

Empirical formula

C12 H20 N6 Ni O6 S2

Formula weight

467.17

Temperature

100(2) K

Wavelength

1.54178 Å

Crystal system

Monoclinic

Space group

P21/n

Unit cell dimensions

a = 8.9893(2) Å

= 90°.

b = 17.6680(5) Å

= 108.609(1)°.

c = 12.5665(3) Å

 = 90°.

Volume

1891.50(8) Å3

Z

4

Density (calculated)

1.641 Mg/m3

Absorption coefficient

3.945 mm-1

F(000)

968

Crystal size

0.18 x 0.15 x 0.14 mm3

Theta range for data collection

4.48 to 68.24°.

Index ranges

-10<=h<=10, -20<=k<=21, -15<=l<=15

Reflections collected

11142

Independent reflections

3448 [R(int) = 0.0455]

Completeness to theta = 66.60°

99.8 %

Absorption correction

Semi-empirical from equivalents

Max. and min. transmission

0.6081 and 0.39725

Refinement method

Full-matrix least-squares on F2

Data / restraints / parameters

3448 / 2 / 292

Goodness-of-fit on F2

1.011

Final R indices [I>2sigma(I)]

R1 = 0.0330, wR2 = 0.0823

R indices (all data)

R1 = 0.0412, wR2 = 0.0867

Largest diff. peak and hole

0.573 and -0.358 e.Å-3

Table 1a: Crystal and structure refinement data using conventional Cu X-ray source

Identification code

Ni Complex 13

Empirical formula

C12 H20 N6 Ni O6 S2

Formula weight

467.16

Temperature

100(2) K

Wavelength

0.61990 Å

Crystal system

Monoclinic

Space group

P21/n

Unit cell dimensions

a = 9.0000(18) Å

= 90°.

b = 17.700(4) Å

= 108.61(3)°.

c = 12.590(3) Å

 = 90°.

Volume

1900.7(7) Å3

Z

4

Density (calculated)

1.632 Mg/m3

Absorption coefficient

0.821 mm-1

F(000)

968

Crystal size

0.30 x 0.50 x 0.50 mm3

Theta range for data collection

1.80 to 25.12°.

Index ranges

-12<=h<=12, -23<=k<=23, -17<=l<=17

Reflections collected

28469

Independent reflections

5011 [R(int) = 0.0205]

Completeness to theta = 25.12°

98.0 %

Max. and min. transmission

0.7908 and 0.6844

Refinement method

Full-matrix least-squares on F2

Data / restraints / parameters

5011 / 0 / 325

Goodness-of-fit on F2

1.118

Final R indices [I>2sigma(I)]

R1 = 0.0220, wR2 = 0.0587

R indices (all data)

R1 = 0.0220, wR2 = 0.0587

Extinction coefficient

0.0342(12)

Largest diff. peak and hole

0.467 and -0.490 e.Å-3

Table 1b: Crystal and structure refinement data using Synchrotron X-ray source

Compound

%C Found (calculated)

%H Found (calculated)

%N Found (calculated

%S Found (calculated)

%Ni Found (calculated)

2-hydroxy-pyridine-N- oxide (HL)

 54.437
(54.054)

   4.189
(4.504)

 11.989
(12.612)

      -

       -

[NiL2(SCN)2].(NH4)2 2H2O

  29.05
(30.855)

   5.14
(4.315)

  17.28
(17.99)

 13.800
(13.73)

13.73
(12.524)

Table 2: Analytical data for the ligand and [NiL2(SCN)2].(NH4)2 2H2O complex.

Compound

νH2O

ν OH

ν CH

δO…HO

ν N-O

ν SCN

νNH4+

 δ NO
bending

ν NH4+
bending

 ν M-O
ν M-N

2-hydroxy-pyridinum-N- oxide (HL)

3331

2973
2900

1446

880     
842

[NiL2(SCN)2.]. 2NH2 .2H2O

3467

2987

1548

1568

2148
2082

3214

883
837

1394

457                          427 

Table 3: IR band assignments (cm-1) for the ligand and Ni(II) complex.

D-H...A

d(D-H)

d(H...A)

d(D...A)

<(DHA)

N(6)-H(6F)...O(5)

0.91(4)

2.06(4)

2.965(3)

172(3)

 N(6)-H(6E)...O(2)#1

0.94(4)

1.92(4)

2.823(3)

162(3)

 N(5)-H(5F)...S(2)#2

0.91(3)

2.38(3)

3.281(2)

171(3)

 N(5)-H(5E)...N(1)

0.94(4)

2.68(4)

3.511(3)

149(3)

 N(5)-H(5E)...O(4)

0.94(4)

1.87(4)

2.783(3)

164(3)

 N(5)-H(5D)...O(5)

0.97(3)

1.98(3)

2.818(3)

143(3)

 N(5)-H(5C)...S(1)#1

0.94(4)

2.42(4)

3.312(2)

158(3)

 O(5)-H(5A)...N(4)#2

0.81(3)

2.67(3)

3.400(2)

150(4)

 O(5)-H(5A)...N(3)#2

0.81(3)

2.41(3)

3.038(2)

135(4)

Symmetry transformations used to generate equivalent atoms: #1 x+1/2,-y+1/2,z-1/2 #2 x+1,y,z
Table 4: Hydrogen bond geometry [Å and °].

Data Collection
Method

Resolution Achieved

Total Number of Reflections Measured

Number of Symmetry Independent Reflections

R(int)

R1 for I>2s(I)

Conventional Laboratory Diffractometer

1.00Å

11,142

3448

0.0455

0.0330

Diamond Synchrotron Pilatus

0.73 Å

28,469

5011

0.0205

0.0220

Table 5a: Comparison of Data and Refinement Parameters

Data Collection Method

    Typical Bond Length esd's Å

   Typical Bond Angle esd's o

C – C

S – C

Ni –O

C - C - C

O – Ni - O

Conventional Laboratory Diffractometer

0.003

0.002

0.002

0.2

0.06

Diamond Synchrotron Pilatus

0.001

0.001

0.0008

0.1

0.03

Table 5b: Comparison of Molecular Geometry esd's

Figure 1: Scheme for the synthesis of the Ni(II) complex: [NiL2(SCN)2].(NH4)2 2H2O.
Figure 2: MERCURY [39] plot derived from the X-ray structure of the Ni(II) complex: [NiL2(SCN)2].(NH4)2 2H2O. The atom numbering used in the two X-ray structure analyses is shown.
Figure 3a: Ortep [19] plot rendered by RASTER 3D [20] excluding the NH4+ and H2O solvates. Thermal ellipsoids are drawn at 95% probability.
Figure 3b: Distorted octahedral coordination of the Ni atom (green) by 2 N atoms (blue) and 4 O atoms (red) drawn with MERCURY [39].
Figure 4: TGA and DTA curves of [NiL2(SCN)2].(NH4)2 2H2O. The a and b parameters used in the calculation of the asymmetry As of an endotherm trough on the DTA curve are indicated. The asymmetry of an exotherm peak can be derived using a comparable method.
Figure 5: Measurements of Δt values made on the DTA curve corresponding to different temperatures.
Figure 6: Selected H-bonds in the crystal structure. Drawn with MERCURY [39]. See also Table 4.