Di-μ-chlorido-bis­({9-[(2,6-diisopropyl­phen­yl)imino­meth­yl]anthracen-1-yl}palladium(II))

Zhou, J.; Wang, Q.; Sun, H.

doi:10.1107/S1600536808010301

metal-organic compounds

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ISSN: 2056-9890

Volume 64| Part 5| May 2008| Page m688

doi:10.1107/S1600536808010301

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Di-μ-chlorido-bis({9-[(2,6-diisopropylphenyl)iminomethyl]anthracen-1-yl}palladium(II))

Jin Zhou,^a Qibao Wang ^a and Hongjian Sun ^a ^*

^aSchool of Chemistry and Chemical Engineering, Shandong University, Shanda Nanlu 27, Jinan 250100, People's Republic of China
^*Correspondence e-mail: hjsun@sdu.edu.cn

(Received 18 March 2008; accepted 15 April 2008; online 23 April 2008)

The centrosymmetric title compound, [Pd₂Cl₂(C₂₇H₂₆N)₂], was obtained by a C—H bond-activation reaction of a Schiff base ligand with Li₂PdCl₄ in methanol, and was crystallized from dichloromethane as orange crystals. The Pd atom displays a slightly distorted square-planar geometry, with the N- and C-atom donors in a cis arrangement.

Related literature

An imine palladacycle crystal structure with a six-membered ring has been determined (Munno et al. 1995 ). For related literature, see: Dupont et al. (2005 ).

Experimental

Crystal data

[Pd₂Cl₂(C₂₇H₂₆N)₂]
M_r = 1012.68
Monoclinic, P 2₁ /n
a = 12.3002 (4) Å
b = 12.9836 (4) Å
c = 15.4558 (5) Å
β = 110.364 (2)°
V = 2314.04 (13) Å³
Z = 2
Mo Kα radiation
μ = 0.93 mm⁻¹
T = 298 (2) K
0.20 × 0.18 × 0.15 mm

Data collection

Bruker SMART APEXII diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ) T_min = 0.836, T_max = 0.873
27723 measured reflections
5320 independent reflections
2428 reflections with I > 2σ(I)
R_int = 0.101

Refinement

R[F² > 2σ(F²)] = 0.050
wR(F²) = 0.131
S = 0.94
5320 reflections
271 parameters
H-atom parameters constrained
Δρ_max = 0.58 e Å⁻³
Δρ_min = −0.54 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ); cell refinement: APEX2; data reduction: SAINT (Bruker, 1997 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808010301/cs2073sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808010301/cs2073Isup2.hkl

checkCIF report

Comment top

Recently, much attention is being paid to the use of palladacycles as catalyst precursors (Dupont et al. 2005). Several imine-palladacycles with six-membered rings were prepared as catalyst precursors (Munno et al. 1995). We prepared a new palladacycle with six-membered ring by a C—H bond activation reaction between a Schiff base ligand and Li₂PdCl₄ in methanol. In its orange crystals palladium displays a slightly distorted square-planar geometry with the nitrogen and the carbon donors in cis-fashion. The length of C26—N1 (1.292 (6) Å) is characteristic for a C=N double bond. The distances of Pd—Cl bond trans to the carbon donor are slightly longer (ca 0.12 Å) than those trans to the imine donor, as expected, because of the trans influence. The chelate ring of Pd1—N1—C26—C27—C24—C23 adopts a twisted half-chair conformation, which is due to the presence of three double bonds of N1—C26, C23—C24 and C24—C27 in the ring. The isopropyl groups on the aromatic ring may readily force the N-phenyl ring perpendicular to the coordination plane.

Related literature top

An imine palladacycle crystal structure with a six-membered ring has been determined (Munno et al. 1995).

For related literature, see: Dupont et al. (2005).

Experimental top

Anthracen-9-ylmethylene-(2,6-di-isopropylphenyl)-amine (383 mg, 1.05 mmol) was mixed with Li₂PdCl₄ (262 mg, 1 mmol) and NaOAc (86 mg, 1.05 mmol) in 5 ml of methanol. The reaction mixture was stirred for 3 days. The title compound was filtrated and dried under vacuo in the yield of 65% (329 mg). The crystals suitable for X-ray analysis were obtained from a dichloromethane solution by slow evaporation at room temperatures.

Computing details top

Data collection: SMART (Bruker, 1997); cell refinement: SMART (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. Molecular structure of the title compound. Displacement ellipsoids are drawn at 30% probability level, symmetry code A: 0.5-X, 0.5+Y, 0.5-Z

Di-µ-chlorido-bis({9-[(2,6-diisopropylphenyl)iminomethyl]anthracen-1- yl}palladium(II)) top

Crystal data top

[Pd₂Cl₂(C₂₇H₂₆N)₂]	F(000) = 1032
M_r = 1012.68	D_x = 1.453 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 12.3002 (4) Å	Cell parameters from 2187 reflections
b = 12.9836 (4) Å	θ = 2.4–18.8°
c = 15.4558 (5) Å	µ = 0.93 mm⁻¹
β = 110.364 (2)°	T = 298 K
V = 2314.04 (13) Å³	Block, orange
Z = 2	0.20 × 0.18 × 0.15 mm

Data collection top

Bruker SMART APEXII diffractometer	5320 independent reflections
Radiation source: fine-focus sealed tube	2428 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.101
ϕ and ω scans	θ_max = 27.5°, θ_min = 1.8°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −16→14
T_min = 0.836, T_max = 0.873	k = −16→16
27723 measured reflections	l = −19→20

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.131	H-atom parameters constrained
S = 0.94	w = 1/[σ²(F_o²) + (0.0537P)²] where P = (F_o² + 2F_c²)/3
5320 reflections	(Δ/σ)_max < 0.001
271 parameters	Δρ_max = 0.58 e Å⁻³
0 restraints	Δρ_min = −0.54 e Å⁻³

Crystal data top

[Pd₂Cl₂(C₂₇H₂₆N)₂]	V = 2314.04 (13) Å³
M_r = 1012.68	Z = 2
Monoclinic, P2₁/n	Mo Kα radiation
a = 12.3002 (4) Å	µ = 0.93 mm⁻¹
b = 12.9836 (4) Å	T = 298 K
c = 15.4558 (5) Å	0.20 × 0.18 × 0.15 mm
β = 110.364 (2)°

Data collection top

Bruker SMART APEXII diffractometer	5320 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	2428 reflections with I > 2σ(I)
T_min = 0.836, T_max = 0.873	R_int = 0.101
27723 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.131	H-atom parameters constrained
S = 0.94	Δρ_max = 0.58 e Å⁻³
5320 reflections	Δρ_min = −0.54 e Å⁻³
271 parameters

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

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

	x	y	z	U_iso*/U_eq
Pd1	0.40636 (3)	0.49507 (3)	0.06810 (3)	0.04914 (17)
C27	0.1926 (4)	0.4388 (4)	0.1521 (3)	0.0411 (13)
Cl3	0.57537 (14)	0.40623 (14)	0.05309 (12)	0.0827 (6)
N1	0.3915 (3)	0.3993 (3)	0.1645 (3)	0.0395 (10)
C26	0.3002 (4)	0.3840 (4)	0.1860 (3)	0.0426 (13)
H26A	0.3049	0.3316	0.2282	0.051*
C25	0.0810 (4)	0.5956 (4)	0.0888 (4)	0.0485 (14)
C24	0.1851 (4)	0.5348 (4)	0.1064 (3)	0.0400 (13)
C23	0.2731 (4)	0.5759 (4)	0.0773 (3)	0.0466 (14)
C22	0.0973 (4)	0.4010 (4)	0.1764 (4)	0.0496 (14)
C21	0.5028 (4)	0.2374 (4)	0.1872 (3)	0.0429 (13)
C20	0.1011 (5)	0.3082 (5)	0.2267 (4)	0.0666 (18)
H20A	0.1682	0.2684	0.2455	0.080*
C19	0.5995 (5)	0.1817 (4)	0.2388 (4)	0.0545 (16)
H19A	0.6084	0.1145	0.2217	0.065*
C18	−0.0089 (5)	0.4584 (5)	0.1491 (4)	0.0492 (14)
C17	0.5775 (4)	0.3840 (4)	0.2893 (4)	0.0447 (13)
C16	0.4925 (4)	0.3376 (4)	0.2149 (3)	0.0414 (13)
C15	0.5675 (5)	0.4939 (4)	0.3150 (4)	0.0560 (15)
H15A	0.5160	0.5288	0.2597	0.067*
C14	−0.0114 (5)	0.5520 (5)	0.1076 (4)	0.0573 (16)
H14A	−0.0803	0.5892	0.0907	0.069*
C13	0.6832 (5)	0.2241 (5)	0.3152 (4)	0.0572 (16)
H13A	0.7471	0.1854	0.3500	0.069*
C12	0.2641 (5)	0.6770 (5)	0.0496 (4)	0.0666 (18)
H12A	0.3250	0.7058	0.0353	0.080*
C11	0.0777 (6)	0.6980 (5)	0.0583 (4)	0.0668 (18)
H11A	0.0115	0.7372	0.0498	0.080*
C10	0.1665 (6)	0.7400 (5)	0.0415 (5)	0.077 (2)
H10A	0.1651	0.8090	0.0249	0.092*
C9	0.6706 (5)	0.3239 (5)	0.3391 (4)	0.0572 (16)
H9A	0.7269	0.3521	0.3907	0.069*
C8	0.4119 (5)	0.1866 (4)	0.1027 (4)	0.0578 (16)
H8A	0.3638	0.2416	0.0650	0.069*
C7	−0.1044 (5)	0.4211 (5)	0.1699 (5)	0.0684 (19)
H7A	−0.1740	0.4571	0.1494	0.082*
C6	0.0057 (5)	0.2770 (5)	0.2479 (5)	0.081 (2)
H6A	0.0096	0.2172	0.2819	0.097*
C5	−0.0964 (6)	0.3348 (6)	0.2185 (6)	0.087 (2)
H5A	−0.1599	0.3128	0.2331	0.105*
C4	0.3321 (5)	0.1145 (5)	0.1306 (5)	0.095 (2)
H4A	0.2759	0.0854	0.0763	0.142*
H4B	0.2931	0.1525	0.1645	0.142*
H4C	0.3771	0.0603	0.1687	0.142*
C3	0.5130 (7)	0.5030 (5)	0.3888 (5)	0.101 (2)
H3A	0.4396	0.4681	0.3688	0.152*
H3B	0.5015	0.5744	0.3994	0.152*
H3C	0.5633	0.4723	0.4450	0.152*
C2	0.4703 (6)	0.1313 (6)	0.0437 (5)	0.103 (3)
H2A	0.5176	0.1792	0.0252	0.154*
H2B	0.4122	0.1033	−0.0102	0.154*
H2C	0.5180	0.0766	0.0787	0.154*
C1	0.6817 (6)	0.5514 (5)	0.3466 (5)	0.095 (2)
H1A	0.7167	0.5465	0.3001	0.143*
H1B	0.7326	0.5217	0.4030	0.143*
H1C	0.6682	0.6225	0.3567	0.143*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Pd1	0.0378 (2)	0.0662 (3)	0.0482 (3)	0.0092 (2)	0.02099 (18)	0.0192 (2)
C27	0.040 (3)	0.051 (4)	0.037 (3)	0.002 (3)	0.018 (3)	−0.004 (3)
Cl3	0.0636 (10)	0.1143 (14)	0.0903 (13)	0.0401 (10)	0.0520 (10)	0.0621 (11)
N1	0.034 (2)	0.043 (3)	0.042 (3)	0.0013 (19)	0.014 (2)	0.007 (2)
C26	0.038 (3)	0.043 (3)	0.049 (3)	0.003 (2)	0.017 (3)	0.010 (3)
C25	0.043 (3)	0.060 (4)	0.044 (3)	0.004 (3)	0.018 (3)	−0.004 (3)
C24	0.037 (3)	0.053 (4)	0.033 (3)	0.003 (2)	0.016 (2)	−0.003 (2)
C23	0.051 (3)	0.045 (4)	0.044 (3)	0.006 (3)	0.016 (3)	0.007 (3)
C22	0.045 (3)	0.056 (4)	0.053 (4)	0.001 (3)	0.022 (3)	−0.002 (3)
C21	0.039 (3)	0.059 (4)	0.036 (3)	0.005 (3)	0.020 (3)	0.010 (3)
C20	0.045 (4)	0.068 (4)	0.088 (5)	−0.004 (3)	0.026 (3)	0.009 (4)
C19	0.048 (4)	0.049 (4)	0.074 (5)	0.010 (3)	0.031 (3)	0.012 (3)
C18	0.043 (3)	0.059 (4)	0.050 (4)	0.006 (3)	0.021 (3)	−0.005 (3)
C17	0.038 (3)	0.060 (4)	0.038 (3)	−0.005 (3)	0.015 (3)	0.010 (3)
C16	0.035 (3)	0.058 (4)	0.038 (3)	0.007 (3)	0.022 (3)	0.016 (3)
C15	0.056 (3)	0.057 (4)	0.050 (3)	−0.008 (3)	0.012 (3)	−0.002 (3)
C14	0.052 (4)	0.070 (4)	0.051 (4)	0.015 (3)	0.020 (3)	−0.008 (3)
C13	0.043 (3)	0.067 (4)	0.059 (4)	0.004 (3)	0.014 (3)	0.022 (3)
C12	0.071 (4)	0.074 (5)	0.064 (4)	0.009 (4)	0.036 (4)	0.013 (4)
C11	0.081 (5)	0.062 (4)	0.070 (5)	0.024 (4)	0.042 (4)	0.007 (4)
C10	0.102 (6)	0.052 (4)	0.090 (5)	0.021 (4)	0.051 (5)	0.023 (4)
C9	0.049 (4)	0.071 (5)	0.045 (4)	−0.010 (3)	0.009 (3)	0.010 (3)
C8	0.055 (4)	0.055 (4)	0.057 (4)	0.004 (3)	0.012 (3)	−0.003 (3)
C7	0.044 (4)	0.079 (5)	0.089 (5)	−0.001 (3)	0.033 (4)	−0.024 (4)
C6	0.065 (4)	0.077 (5)	0.109 (6)	−0.013 (4)	0.041 (4)	0.014 (4)
C5	0.052 (4)	0.091 (6)	0.139 (7)	−0.011 (4)	0.058 (5)	−0.012 (5)
C4	0.068 (5)	0.108 (6)	0.096 (6)	−0.031 (4)	0.013 (4)	−0.006 (5)
C3	0.130 (7)	0.079 (5)	0.116 (6)	−0.017 (5)	0.070 (6)	−0.033 (5)
C2	0.079 (5)	0.122 (7)	0.097 (6)	0.011 (4)	0.018 (5)	−0.048 (5)
C1	0.085 (6)	0.072 (5)	0.124 (7)	−0.022 (4)	0.030 (5)	−0.003 (5)

Geometric parameters (Å, º) top

Pd1—C23	1.992 (5)	C15—C3	1.516 (8)
Pd1—N1	1.997 (4)	C15—H15A	0.9800
Pd1—Cl3ⁱ	2.3440 (15)	C14—H14A	0.9300
Pd1—Cl3	2.4580 (15)	C13—C9	1.370 (7)
C27—C24	1.420 (7)	C13—H13A	0.9300
C27—C22	1.436 (7)	C12—C10	1.421 (8)
C27—C26	1.431 (6)	C12—H12A	0.9300
Cl3—Pd1ⁱ	2.3440 (15)	C11—C10	1.326 (8)
N1—C26	1.292 (6)	C11—H11A	0.9300
N1—C16	1.456 (6)	C10—H10A	0.9300
C26—H26A	0.9300	C9—H9A	0.9300
C25—C11	1.405 (7)	C8—C2	1.523 (8)
C25—C14	1.388 (7)	C8—C4	1.522 (8)
C25—C24	1.448 (7)	C8—H8A	0.9800
C24—C23	1.413 (7)	C7—C5	1.333 (8)
C23—C12	1.374 (7)	C7—H7A	0.9300
C22—C20	1.426 (7)	C6—C5	1.396 (8)
C22—C18	1.434 (7)	C6—H6A	0.9300
C21—C16	1.388 (7)	C5—H5A	0.9300
C21—C19	1.383 (7)	C4—H4A	0.9600
C21—C8	1.542 (7)	C4—H4B	0.9600
C20—C6	1.384 (7)	C4—H4C	0.9600
C20—H20A	0.9300	C3—H3A	0.9600
C19—C13	1.383 (7)	C3—H3B	0.9600
C19—H19A	0.9300	C3—H3C	0.9600
C18—C14	1.370 (7)	C2—H2A	0.9600
C18—C7	1.407 (8)	C2—H2B	0.9600
C17—C9	1.378 (7)	C2—H2C	0.9600
C17—C16	1.394 (7)	C1—H1A	0.9600
C17—C15	1.498 (7)	C1—H1B	0.9600
C15—C1	1.514 (7)	C1—H1C	0.9600

C23—Pd1—N1	89.05 (19)	C9—C13—C19	119.1 (5)
C23—Pd1—Cl3ⁱ	94.53 (16)	C9—C13—H13A	120.5
N1—Pd1—Cl3ⁱ	174.64 (12)	C19—C13—H13A	120.5
C23—Pd1—Cl3	176.05 (17)	C23—C12—C10	123.5 (6)
N1—Pd1—Cl3	94.50 (12)	C23—C12—H12A	118.3
Cl3ⁱ—Pd1—Cl3	82.05 (5)	C10—C12—H12A	118.3
C24—C27—C22	120.8 (5)	C10—C11—C25	121.7 (6)
C24—C27—C26	120.7 (4)	C10—C11—H11A	119.2
C22—C27—C26	118.0 (5)	C25—C11—H11A	119.2
Pd1ⁱ—Cl3—Pd1	97.95 (5)	C11—C10—C12	118.3 (6)
C26—N1—C16	115.7 (4)	C11—C10—H10A	120.8
C26—N1—Pd1	127.0 (3)	C12—C10—H10A	120.8
C16—N1—Pd1	117.3 (3)	C17—C9—C13	122.3 (5)
N1—C26—C27	127.2 (5)	C17—C9—H9A	118.8
N1—C26—H26A	116.4	C13—C9—H9A	118.8
C27—C26—H26A	116.4	C2—C8—C4	111.4 (6)
C11—C25—C14	121.7 (6)	C2—C8—C21	110.8 (5)
C11—C25—C24	119.9 (5)	C4—C8—C21	111.8 (5)
C14—C25—C24	118.3 (5)	C2—C8—H8A	107.5
C27—C24—C23	124.4 (5)	C4—C8—H8A	107.5
C27—C24—C25	118.2 (5)	C21—C8—H8A	107.5
C23—C24—C25	117.4 (5)	C5—C7—C18	121.0 (6)
C12—C23—C24	118.2 (5)	C5—C7—H7A	119.5
C12—C23—Pd1	117.4 (4)	C18—C7—H7A	119.5
C24—C23—Pd1	124.4 (4)	C20—C6—C5	120.5 (6)
C27—C22—C20	123.8 (5)	C20—C6—H6A	119.8
C27—C22—C18	119.3 (5)	C5—C6—H6A	119.8
C20—C22—C18	116.9 (5)	C7—C5—C6	121.0 (6)
C16—C21—C19	117.7 (5)	C7—C5—H5A	119.5
C16—C21—C8	123.0 (5)	C6—C5—H5A	119.5
C19—C21—C8	119.2 (5)	C8—C4—H4A	109.5
C6—C20—C22	120.4 (6)	C8—C4—H4B	109.5
C6—C20—H20A	119.8	H4A—C4—H4B	109.5
C22—C20—H20A	119.8	C8—C4—H4C	109.5
C13—C19—C21	121.3 (5)	H4A—C4—H4C	109.5
C13—C19—H19A	119.4	H4B—C4—H4C	109.5
C21—C19—H19A	119.4	C15—C3—H3A	109.5
C14—C18—C7	121.9 (6)	C15—C3—H3B	109.5
C14—C18—C22	117.9 (5)	H3A—C3—H3B	109.5
C7—C18—C22	120.1 (6)	C15—C3—H3C	109.5
C9—C17—C16	117.1 (5)	H3A—C3—H3C	109.5
C9—C17—C15	121.4 (5)	H3B—C3—H3C	109.5
C16—C17—C15	121.5 (5)	C8—C2—H2A	109.5
C21—C16—C17	122.4 (5)	C8—C2—H2B	109.5
C21—C16—N1	120.2 (5)	H2A—C2—H2B	109.5
C17—C16—N1	117.4 (5)	C8—C2—H2C	109.5
C17—C15—C1	113.7 (5)	H2A—C2—H2C	109.5
C17—C15—C3	111.9 (5)	H2B—C2—H2C	109.5
C1—C15—C3	108.8 (5)	C15—C1—H1A	109.5
C17—C15—H15A	107.4	C15—C1—H1B	109.5
C1—C15—H15A	107.4	H1A—C1—H1B	109.5
C3—C15—H15A	107.4	C15—C1—H1C	109.5
C18—C14—C25	125.0 (6)	H1A—C1—H1C	109.5
C18—C14—H14A	117.5	H1B—C1—H1C	109.5
C25—C14—H14A	117.5

Symmetry code: (i) −x+1, −y+1, −z.

Experimental details

Crystal data
Chemical formula	[Pd₂Cl₂(C₂₇H₂₆N)₂]
M_r	1012.68
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	298
a, b, c (Å)	12.3002 (4), 12.9836 (4), 15.4558 (5)
β (°)	110.364 (2)
V (Å³)	2314.04 (13)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.93
Crystal size (mm)	0.20 × 0.18 × 0.15

Data collection
Diffractometer	Bruker SMART APEXII diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1996)
T_min, T_max	0.836, 0.873
No. of measured, independent and observed [I > 2σ(I)] reflections	27723, 5320, 2428
R_int	0.101
(sin θ/λ)_max (Å⁻¹)	0.650

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.131, 0.94
No. of reflections	5320
No. of parameters	271
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.58, −0.54

Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

Financial support of this work by the Excellent Young Teachers Program of MOE, People's Republic of China, and by the Scientific Research Foundation for Returned Overseas Chinese Scholars/State Education Ministry, Natural Science Foundation of Shandong University for Young Scientists, are gratefully acknowledged.

References

Bruker (1997). SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2005). APEX2. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
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Munno, G. D., Ghedini, M. & Neve, F. (1995). Inorg. Chim. Acta, 239, 155–158. CSD CrossRef Web of Science Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar

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