PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of actaeInternational Union of Crystallographysearchopen accessarticle submissionjournal home pagethis article
 
Acta Crystallogr Sect E Struct Rep Online. 2010 October 1; 66(Pt 10): m1246.
Published online 2010 September 11. doi:  10.1107/S1600536810035890
PMCID: PMC2983194

{6,6′-Dimeth­oxy-2,2′-[4,5-dimethyl-o-phenyl­enebis(nitrilo­methyl­idyne)]diphenolato}nickel(II)

Abstract

In the title Schiff base complex, [Ni(C24H22N2O4)], the NiII atom has a slightly distorted square-planar coordination environment. The dihedral angles between the central benzene ring and the two outer rings are 7.62 (16) and 9.78 (17)°. The crystal structure is stabilized by inter­molecular C—H(...)O hydrogen bonds and π–π inter­actions with a centroid–centroid distance of 3.8218 (19) Å.

Related literature

For background to Schiff base–metal complexes, see: Granovski et al. (1993 [triangle]); Blower et al. (1998 [triangle]); Elmali et al. (2000 [triangle]). For standard values of bond lengths, see: Allen et al. (1987 [triangle]).

An external file that holds a picture, illustration, etc.
Object name is e-66-m1246-scheme1.jpg

Experimental

Crystal data

  • [Ni(C24H22N2O4)]
  • M r = 461.15
  • Monoclinic, An external file that holds a picture, illustration, etc.
Object name is e-66-m1246-efi1.jpg
  • a = 12.8057 (6) Å
  • b = 12.6514 (5) Å
  • c = 13.0263 (6) Å
  • β = 101.730 (2)°
  • V = 2066.32 (16) Å3
  • Z = 4
  • Mo Kα radiation
  • μ = 0.97 mm−1
  • T = 296 K
  • 0.24 × 0.14 × 0.08 mm

Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.800, T max = 0.926
  • 36150 measured reflections
  • 5146 independent reflections
  • 3179 reflections with I > 2σ(I)
  • R int = 0.068

Refinement

  • R[F 2 > 2σ(F 2)] = 0.047
  • wR(F 2) = 0.124
  • S = 1.03
  • 5146 reflections
  • 284 parameters
  • H-atom parameters constrained
  • Δρmax = 0.48 e Å−3
  • Δρmin = −0.34 e Å−3

Data collection: APEX2 (Bruker, 2005 [triangle]); cell refinement: SAINT (Bruker, 2005 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 [triangle]); molecular graphics: SHELXTL (Sheldrick, 2008 [triangle]); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810035890/su2210sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810035890/su2210Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Acknowledgments

HK and AS thank PNU for financial support. RK thanks the Islamic Azad University. MNT thanks the University of Sargodha, Pakistan, for the research facilities.

supplementary crystallographic information

Comment

Schiff base complexes are one of the most important stereochemical models in transition metal coordination chemistry, with ease of preparation and structural variations (Granovski et al., 1993). Metal derivatives of the Schiff bases have been studied extensively, and nickel(II) and copper(II) complexes play a major role in both synthetic and structurel research (Elmali et al., 2000; Blower et al., 1998).

The molecular structure of the title molecule is illustrated in Fig. 1. The bond lengths (Allen et al., 1987) and angles are within normal ranges. The geometry around the NiII atom is square-planar being coordinated by the N2O2 donor atoms of the tetradenate Schiff base ligand. The dihedral angle between the mean planes of the central aromatic ring (C9-C14) with the two outer rings (C1-C6 and C18-C23) are 7.62 (16) and 9.78 (17)°, respectively.

The crystal structure is stabilized by intermolecular C—H···O hydrogen bonds (Table 1) and π–π interactions [Cg1···Cg2i = 3.8218 (19)Å; Cg1 and Cg2 are the centroids of the C1-C6 and C9-C14 rings, respectively; symmetry code (i) -x, 2-y, -z].

Experimental

The title compound was synthesized by adding bis(6-methoxysalicylidene)-4,5-dimethyl phenylenediamine (2 mmol) to a solution of NiCl2.6H2O (2 mmol) in ethanol (30 ml). The mixture was refluxed with stirring for 30 min. The resultant red solution was filtered. Dark-red plate-like single crystals of the title compound, suitable for X-ray structure analysis, were obtained by slow evaporation at RT of a solution in ethanol over a period of several days.

Refinement

All the H-atoms were positioned geometrically and included in a riding model approximation: C—H = 0.93 and 0.96 Å for CH and CH3 H-atoms, respectively, with Uiso(H) = k × Ueq (C), where k = 1.5 for methyl H-atoms and k = 1.2 for all other H-atoms.

Figures

Fig. 1.
The molecular structure of the title molecule, showing 40% probability displacement ellipsoids and the atom numbering scheme.
Fig. 2.
The crystal packing diagram of the title compound viewed down the c-axis showing intermolecular interactions as dashed lines.

Crystal data

[Ni(C24H22N2O4)]F(000) = 960
Mr = 461.15Dx = 1.482 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ynCell parameters from 2525 reflections
a = 12.8057 (6) Åθ = 2.5–29.5°
b = 12.6514 (5) ŵ = 0.97 mm1
c = 13.0263 (6) ÅT = 296 K
β = 101.730 (2)°Plate, red
V = 2066.32 (16) Å30.24 × 0.14 × 0.08 mm
Z = 4

Data collection

Bruker SMART APEXII CCD area-detector diffractometer5146 independent reflections
Radiation source: fine-focus sealed tube3179 reflections with I > 2σ(I)
graphiteRint = 0.068
[var phi] and ω scansθmax = 28.4°, θmin = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −17→17
Tmin = 0.800, Tmax = 0.926k = −16→16
36150 measured reflectionsl = −17→17

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.047Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.124H-atom parameters constrained
S = 1.03w = 1/[σ2(Fo2) + (0.0484P)2 + 1.1318P] where P = (Fo2 + 2Fc2)/3
5146 reflections(Δ/σ)max < 0.001
284 parametersΔρmax = 0.48 e Å3
0 restraintsΔρmin = −0.34 e Å3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
Ni10.01614 (3)0.78355 (3)0.17262 (3)0.03619 (14)
O10.07749 (19)0.88142 (16)0.27017 (17)0.0481 (6)
O20.21622 (19)1.12212 (16)0.05147 (18)0.0483 (6)
O3−0.02481 (18)0.72048 (16)0.28477 (17)0.0453 (5)
O4−0.2538 (2)0.4558 (2)0.1089 (2)0.0768 (9)
N10.06210 (19)0.84778 (18)0.06261 (19)0.0346 (6)
N2−0.0465 (2)0.68259 (19)0.07723 (19)0.0364 (6)
C10.1314 (3)0.9655 (2)0.2565 (3)0.0410 (7)
C20.1766 (3)1.0258 (3)0.3455 (3)0.0506 (9)
H20.16751.00470.41150.061*
C30.2336 (3)1.1150 (3)0.3353 (3)0.0528 (9)
H30.26381.15280.39530.063*
C40.2480 (3)1.1515 (3)0.2381 (3)0.0506 (9)
H40.28631.21310.23320.061*
C50.2054 (3)1.0954 (2)0.1504 (3)0.0398 (7)
C60.1472 (2)0.9993 (2)0.1570 (2)0.0365 (7)
C70.2852 (3)1.2086 (3)0.0418 (3)0.0536 (9)
H7A0.25841.27170.06830.080*
H7B0.28801.2184−0.03070.080*
H7C0.35551.19390.08130.080*
C80.1120 (2)0.9388 (2)0.0659 (2)0.0367 (7)
H80.12520.96520.00310.044*
C90.0357 (2)0.7889 (2)−0.0328 (2)0.0349 (7)
C100.0623 (3)0.8146 (2)−0.1274 (2)0.0398 (7)
H100.10350.8743−0.13190.048*
C110.0285 (3)0.7528 (3)−0.2154 (3)0.0417 (7)
C12−0.0325 (3)0.6620 (2)−0.2082 (2)0.0407 (7)
C13−0.0573 (3)0.6355 (2)−0.1132 (3)0.0421 (8)
H13−0.09660.5746−0.10800.050*
C14−0.0241 (2)0.6985 (2)−0.0250 (2)0.0347 (7)
C150.0579 (3)0.7840 (3)−0.3177 (3)0.0583 (10)
H15A0.09720.8491−0.30860.087*
H15B−0.00580.7932−0.37030.087*
H15C0.10100.7295−0.33940.087*
C16−0.0759 (3)0.5964 (3)−0.3041 (3)0.0534 (9)
H16A−0.10540.5320−0.28330.080*
H16B−0.01940.5800−0.33990.080*
H16C−0.13060.6353−0.35010.080*
C17−0.1087 (3)0.6065 (2)0.0954 (2)0.0405 (7)
H17−0.13820.56320.03930.049*
C18−0.1353 (3)0.5845 (2)0.1932 (3)0.0406 (7)
C19−0.2085 (3)0.5008 (3)0.2020 (3)0.0520 (9)
C20−0.2290 (3)0.4723 (3)0.2968 (3)0.0583 (10)
H20−0.27670.41800.30160.070*
C21−0.1776 (3)0.5255 (3)0.3863 (3)0.0554 (10)
H21−0.19060.50490.45110.067*
C22−0.1088 (3)0.6069 (3)0.3820 (3)0.0514 (9)
H22−0.07580.64080.44350.062*
C23−0.0873 (3)0.6399 (2)0.2851 (3)0.0420 (8)
C24−0.3272 (5)0.3705 (4)0.1122 (4)0.107 (2)
H24A−0.28940.31090.14730.161*
H24B−0.36060.35070.04200.161*
H24C−0.38080.39280.14950.161*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
Ni10.0430 (3)0.0344 (2)0.0338 (2)−0.00055 (18)0.01401 (17)−0.00004 (17)
O10.0676 (16)0.0428 (12)0.0370 (13)−0.0083 (11)0.0177 (12)−0.0029 (10)
O20.0570 (15)0.0408 (12)0.0511 (15)−0.0117 (11)0.0203 (12)−0.0070 (10)
O30.0599 (14)0.0443 (12)0.0366 (12)−0.0058 (11)0.0210 (11)0.0005 (10)
O40.096 (2)0.0802 (18)0.0535 (17)−0.0504 (17)0.0144 (16)0.0106 (15)
N10.0350 (14)0.0370 (13)0.0337 (14)−0.0019 (10)0.0117 (11)−0.0013 (11)
N20.0425 (15)0.0360 (12)0.0342 (14)−0.0006 (11)0.0158 (12)0.0034 (11)
C10.0447 (19)0.0377 (16)0.0426 (19)0.0038 (14)0.0134 (15)−0.0060 (14)
C20.066 (2)0.0485 (19)0.038 (2)0.0014 (17)0.0135 (18)−0.0058 (15)
C30.058 (2)0.053 (2)0.045 (2)−0.0070 (17)0.0061 (18)−0.0139 (17)
C40.052 (2)0.0418 (17)0.058 (2)−0.0081 (15)0.0113 (18)−0.0122 (16)
C50.0378 (18)0.0377 (16)0.046 (2)0.0018 (13)0.0135 (15)−0.0065 (14)
C60.0364 (17)0.0322 (14)0.0420 (19)0.0041 (12)0.0108 (14)−0.0040 (13)
C70.055 (2)0.0467 (18)0.064 (2)−0.0115 (17)0.0230 (19)−0.0006 (17)
C80.0363 (17)0.0362 (15)0.0401 (18)0.0016 (13)0.0140 (14)0.0005 (13)
C90.0370 (17)0.0349 (14)0.0345 (16)−0.0018 (13)0.0114 (13)−0.0044 (13)
C100.0441 (19)0.0398 (16)0.0375 (18)−0.0058 (14)0.0129 (15)−0.0011 (13)
C110.0430 (19)0.0481 (17)0.0375 (18)0.0019 (14)0.0160 (15)−0.0002 (14)
C120.0450 (19)0.0423 (17)0.0376 (18)−0.0009 (14)0.0148 (15)−0.0058 (14)
C130.045 (2)0.0382 (16)0.047 (2)−0.0091 (14)0.0181 (16)−0.0056 (14)
C140.0340 (17)0.0364 (15)0.0358 (17)−0.0010 (12)0.0117 (13)0.0018 (12)
C150.070 (2)0.065 (2)0.045 (2)−0.015 (2)0.0241 (19)−0.0027 (18)
C160.059 (2)0.059 (2)0.045 (2)−0.0130 (18)0.0163 (18)−0.0120 (17)
C170.0442 (19)0.0403 (16)0.0381 (18)−0.0054 (14)0.0107 (15)0.0023 (14)
C180.0422 (19)0.0401 (16)0.0425 (19)0.0005 (14)0.0156 (15)0.0092 (14)
C190.058 (2)0.0480 (19)0.052 (2)−0.0087 (17)0.0170 (19)0.0094 (17)
C200.061 (2)0.055 (2)0.064 (3)−0.0059 (18)0.026 (2)0.0199 (19)
C210.070 (3)0.052 (2)0.054 (2)0.0074 (19)0.034 (2)0.0134 (18)
C220.068 (2)0.0470 (19)0.046 (2)0.0061 (17)0.0270 (19)0.0053 (16)
C230.048 (2)0.0387 (16)0.0425 (19)0.0098 (14)0.0174 (16)0.0082 (14)
C240.139 (5)0.113 (4)0.066 (3)−0.090 (4)0.013 (3)0.008 (3)

Geometric parameters (Å, °)

Ni1—O31.832 (2)C9—C141.391 (4)
Ni1—O11.833 (2)C10—C111.382 (4)
Ni1—N11.845 (2)C10—H100.9300
Ni1—N21.848 (2)C11—C121.402 (4)
O1—C11.299 (4)C11—C151.509 (4)
O2—C51.367 (4)C12—C131.380 (4)
O2—C71.428 (4)C12—C161.509 (4)
O3—C231.297 (4)C13—C141.392 (4)
O4—C191.358 (4)C13—H130.9300
O4—C241.438 (4)C15—H15A0.9600
N1—C81.313 (4)C15—H15B0.9600
N1—C91.430 (4)C15—H15C0.9600
N2—C171.302 (4)C16—H16A0.9600
N2—C141.433 (4)C16—H16B0.9600
C1—C21.410 (4)C16—H16C0.9600
C1—C61.419 (4)C17—C181.411 (4)
C2—C31.365 (5)C17—H170.9300
C2—H20.9300C18—C231.415 (4)
C3—C41.395 (5)C18—C191.434 (4)
C3—H30.9300C19—C201.363 (5)
C4—C51.361 (4)C20—C211.390 (5)
C4—H40.9300C20—H200.9300
C5—C61.437 (4)C21—C221.364 (5)
C6—C81.407 (4)C21—H210.9300
C7—H7A0.9600C22—C231.409 (4)
C7—H7B0.9600C22—H220.9300
C7—H7C0.9600C24—H24A0.9600
C8—H80.9300C24—H24B0.9600
C9—C101.382 (4)C24—H24C0.9600
O3—Ni1—O183.87 (9)C10—C11—C15119.5 (3)
O3—Ni1—N1177.97 (11)C12—C11—C15121.0 (3)
O1—Ni1—N194.67 (10)C13—C12—C11119.4 (3)
O3—Ni1—N294.57 (10)C13—C12—C16119.7 (3)
O1—Ni1—N2178.42 (10)C11—C12—C16120.8 (3)
N1—Ni1—N286.88 (10)C12—C13—C14120.9 (3)
C1—O1—Ni1128.5 (2)C12—C13—H13119.6
C5—O2—C7117.1 (3)C14—C13—H13119.6
C23—O3—Ni1128.4 (2)C9—C14—C13119.4 (3)
C19—O4—C24116.8 (3)C9—C14—N2113.6 (3)
C8—N1—C9120.8 (3)C13—C14—N2127.0 (3)
C8—N1—Ni1126.2 (2)C11—C15—H15A109.5
C9—N1—Ni1112.93 (18)C11—C15—H15B109.5
C17—N2—C14121.3 (3)H15A—C15—H15B109.5
C17—N2—Ni1125.9 (2)C11—C15—H15C109.5
C14—N2—Ni1112.73 (18)H15A—C15—H15C109.5
O1—C1—C2118.1 (3)H15B—C15—H15C109.5
O1—C1—C6123.4 (3)C12—C16—H16A109.5
C2—C1—C6118.5 (3)C12—C16—H16B109.5
C3—C2—C1120.4 (3)H16A—C16—H16B109.5
C3—C2—H2119.8C12—C16—H16C109.5
C1—C2—H2119.8H16A—C16—H16C109.5
C2—C3—C4122.2 (3)H16B—C16—H16C109.5
C2—C3—H3118.9N2—C17—C18125.4 (3)
C4—C3—H3118.9N2—C17—H17117.3
C5—C4—C3119.0 (3)C18—C17—H17117.3
C5—C4—H4120.5C17—C18—C23121.5 (3)
C3—C4—H4120.5C17—C18—C19120.0 (3)
C4—C5—O2124.2 (3)C23—C18—C19118.5 (3)
C4—C5—C6121.0 (3)O4—C19—C20124.9 (3)
O2—C5—C6114.7 (3)O4—C19—C18113.9 (3)
C8—C6—C1121.7 (3)C20—C19—C18121.2 (3)
C8—C6—C5119.4 (3)C19—C20—C21119.1 (3)
C1—C6—C5118.8 (3)C19—C20—H20120.4
O2—C7—H7A109.5C21—C20—H20120.4
O2—C7—H7B109.5C22—C21—C20122.1 (3)
H7A—C7—H7B109.5C22—C21—H21119.0
O2—C7—H7C109.5C20—C21—H21119.0
H7A—C7—H7C109.5C21—C22—C23120.4 (4)
H7B—C7—H7C109.5C21—C22—H22119.8
N1—C8—C6125.1 (3)C23—C22—H22119.8
N1—C8—H8117.5O3—C23—C22118.0 (3)
C6—C8—H8117.5O3—C23—C18123.3 (3)
C10—C9—C14119.8 (3)C22—C23—C18118.7 (3)
C10—C9—N1126.5 (3)O4—C24—H24A109.5
C14—C9—N1113.7 (3)O4—C24—H24B109.5
C9—C10—C11120.9 (3)H24A—C24—H24B109.5
C9—C10—H10119.5O4—C24—H24C109.5
C11—C10—H10119.5H24A—C24—H24C109.5
C10—C11—C12119.5 (3)H24B—C24—H24C109.5
O3—Ni1—O1—C1179.7 (3)C9—C10—C11—C12−0.8 (5)
N1—Ni1—O1—C11.2 (3)C9—C10—C11—C15179.3 (3)
O1—Ni1—O3—C23173.2 (3)C10—C11—C12—C13−0.4 (5)
N2—Ni1—O3—C23−7.1 (3)C15—C11—C12—C13179.5 (3)
O1—Ni1—N1—C8−5.6 (3)C10—C11—C12—C16176.5 (3)
N2—Ni1—N1—C8174.6 (3)C15—C11—C12—C16−3.6 (5)
O1—Ni1—N1—C9175.77 (19)C11—C12—C13—C141.1 (5)
N2—Ni1—N1—C9−4.0 (2)C16—C12—C13—C14−175.8 (3)
O3—Ni1—N2—C178.2 (3)C10—C9—C14—C13−0.6 (4)
N1—Ni1—N2—C17−173.2 (3)N1—C9—C14—C13178.5 (3)
O3—Ni1—N2—C14−174.79 (19)C10—C9—C14—N2−179.4 (3)
N1—Ni1—N2—C143.8 (2)N1—C9—C14—N2−0.3 (4)
Ni1—O1—C1—C2−176.2 (2)C12—C13—C14—C9−0.6 (5)
Ni1—O1—C1—C63.6 (5)C12—C13—C14—N2177.9 (3)
O1—C1—C2—C3−179.7 (3)C17—N2—C14—C9174.4 (3)
C6—C1—C2—C30.4 (5)Ni1—N2—C14—C9−2.8 (3)
C1—C2—C3—C41.2 (6)C17—N2—C14—C13−4.3 (5)
C2—C3—C4—C5−1.1 (5)Ni1—N2—C14—C13178.5 (3)
C3—C4—C5—O2−178.6 (3)C14—N2—C17—C18179.8 (3)
C3—C4—C5—C6−0.7 (5)Ni1—N2—C17—C18−3.4 (5)
C7—O2—C5—C46.2 (5)N2—C17—C18—C23−5.6 (5)
C7—O2—C5—C6−171.8 (3)N2—C17—C18—C19177.4 (3)
O1—C1—C6—C8−5.1 (5)C24—O4—C19—C20−1.2 (6)
C2—C1—C6—C8174.8 (3)C24—O4—C19—C18179.3 (4)
O1—C1—C6—C5178.1 (3)C17—C18—C19—O4−5.8 (5)
C2—C1—C6—C5−2.1 (4)C23—C18—C19—O4177.2 (3)
C4—C5—C6—C8−174.6 (3)C17—C18—C19—C20174.7 (3)
O2—C5—C6—C83.4 (4)C23—C18—C19—C20−2.3 (5)
C4—C5—C6—C12.3 (5)O4—C19—C20—C21−179.5 (4)
O2—C5—C6—C1−179.7 (3)C18—C19—C20—C21−0.1 (6)
C9—N1—C8—C6−175.9 (3)C19—C20—C21—C221.3 (6)
Ni1—N1—C8—C65.6 (4)C20—C21—C22—C23−0.1 (5)
C1—C6—C8—N10.3 (5)Ni1—O3—C23—C22−178.7 (2)
C5—C6—C8—N1177.1 (3)Ni1—O3—C23—C180.8 (4)
C8—N1—C9—C103.6 (5)C21—C22—C23—O3177.2 (3)
Ni1—N1—C9—C10−177.7 (3)C21—C22—C23—C18−2.4 (5)
C8—N1—C9—C14−175.4 (3)C17—C18—C23—O37.0 (5)
Ni1—N1—C9—C143.3 (3)C19—C18—C23—O3−176.0 (3)
C14—C9—C10—C111.3 (5)C17—C18—C23—C22−173.5 (3)
N1—C9—C10—C11−177.6 (3)C19—C18—C23—C223.5 (5)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C7—H7C···O3i0.962.513.424 (5)158
C21—H21···O2ii0.932.523.340 (4)147

Symmetry codes: (i) −x+1/2, y+1/2, −z+1/2; (ii) x−1/2, −y+3/2, z+1/2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SU2210).

References

  • Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19.
  • Blower, P. J. (1998). Transition Met. Chem.23, 109–112.
  • Bruker (2005). APEX2, SAINT and SADABS Bruker AXS Inc., Madison, Wisconsin, USA.
  • Elmali, A., Elerman, Y. & Svoboda, I. (2000). Acta Cryst. C56, 423–424. [PubMed]
  • Granovski, A. D., Nivorozhkin, A. L. & Minkin, V. I. (1993). Coord. Chem. Rev.126, 1–69.
  • Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. [PubMed]
  • Spek, A. L. (2009). Acta Cryst. D65, 148–155. [PMC free article] [PubMed]

Articles from Acta Crystallographica Section E: Structure Reports Online are provided here courtesy of International Union of Crystallography