N,N′-Bis(2,6-diethyl­phen­yl)acenaphthyl­ene-1,2-diimine

Wang, L.; Luo, X.; Gao, B.; Wu, Q.; Mu, Y.

doi:10.1107/S1600536811052901

organic compounds

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ISSN: 2056-9890

Volume 68| Part 1| January 2012| Page o128

doi:10.1107/S1600536811052901

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N,N′-Bis(2,6-diethylphenyl)acenaphthylene-1,2-diimine

Li Wang,^a Xuyang Luo,^b Bo Gao,^a Qiaolin Wu ^a ^* and Ying Mu ^a ^*

^aState Key Laboratory of Supramolecular Structure and Materials, School of Chemistry, Jilin University, Changchun 130012, People's Republic of China, and ^bSchool of Chemistry, Jilin University, Changchun 130012, People's Republic of China
^*Correspondence e-mail: wuql@jlu.edu.cn, ymu@jlu.edu.cn

(Received 9 November 2011; accepted 8 December 2011; online 14 December 2011)

The title compound, C₃₂H₃₂N₂, has crystallographic twofold rotation symmetry, with two C atoms lying on the rotation axis. The dihedral angle between the substituted benzene ring and the naphthalene ring system is 79.8 (1)°. The crystal structure is stabilized by C—H⋯N interactions, which form a chain motif along the b-axis direction.

Related literature

For details and applications of acenaphthenquinone-based Schiff bases and corresponding metal complexes, see: Li et al. (2011 ); Hagar et al. (2010 ); Kovach et al. (2011 ); Oleinik et al. (2005 ); Ragaini et al. (2006 ); Rosa et al. (2008 ); Small et al. (2007 ); Zhou et al. (2008 ).

Experimental

Crystal data

C₃₂H₃₂N₂
M_r = 444.60
Monoclinic, C 2/c
a = 13.5134 (12) Å
b = 8.6952 (8) Å
c = 22.3532 (19) Å
β = 99.413 (1)°
V = 2591.2 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 185 K
0.25 × 0.24 × 0.21 mm

Data collection

Bruker SMART APEX CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.984, T_max = 0.986
7599 measured reflections
2538 independent reflections
1842 reflections with I > 2σ(I)
R_int = 0.028

Refinement

R[F² > 2σ(F²)] = 0.053
wR(F²) = 0.151
S = 1.02
2538 reflections
157 parameters
H-atom parameters constrained
Δρ_max = 0.42 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4⋯N1ⁱ	0.95	2.43	3.379 (2)	179
Symmetry code: (i) x, y+1, z.

Data collection: SMART (Bruker, 1998 ); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; 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 global, I. DOI: 10.1107/S1600536811052901/fy2033sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811052901/fy2033Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811052901/fy2033Isup3.cml

checkCIF report

Comment top

Acenaphthenequinone-based Schiff bases and their metal complexes have been widely synthesized due to their significant applications in catalysis, coordination chemistry and supramolecular assemblies. (Ragaini et al., 2006; Kovach et al., 2011; Small et al., 2007; Rosa et al., 2008; Oleinik et al., 2005; Li et al., 2011; Hagar et al., 2010; Zhou et al., 2008.) As part of our research efforts focused on developing olefin polymerization catalysts, a novel series of Schiff-base derivatives were synthesized and evaluated as high-performance ligand systems. Herein, we report the preparation and crystal structure of new acenaphthenequinone-based Schiff base compound, derived from acenaphthenequinone and 2,6-diethylaniline.

The title molecule, Fig. 1, has crystallographic twofold rotation symmetry. The dihedral angle between the substituted benzene ring and the naphthalene fragment is 79.8 (1)°. Both lengths and angles in the title compound are in normal ranges and are comparable to those found in similar acenaphthenequinone-based Schiff base compounds (Kovach et al., 2011; Rosa et al., 2008).

In the packing of the crystal, there are intermolecular C—H···N interactions, which form one-dimensional chains (Fig. 2 and Table 1).

Related literature top

For details and applications of acenaphthenquinone-based Schiff bases and corresponding metal complexes, see: Li et al. (2011); Hagar et al. (2010); Kovach et al. (2011); Oleinik et al. (2005); Ragaini et al. (2006); Rosa et al. (2008); Small et al. (2007); Zhou et al. (2008).

Experimental top

Acenaphthenequinone (1.35 g, 7.4 mmol) in 65 ml of acetonitrile was heated under reflux for 30 min and then 12 ml of acetic acid was added and heating was continued until the acenaphthenequinone had completely dissolved. To this hot solution, 2.39 g (16 mmol) of 2,6-diethylaniline was added directly and the solution was heated under reflux for a further 1.5 h. It was then cooled to room temperature and the solid filtered off to give a yellow product that was washed with hexane and air dried. Yield 2.73 g (83%). The crystals suitable for X-ray structure determination were obtained by slow solvent evaporation from an ethanolic solution at room temperature.

Computing details top

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT (Bruker, 1998); 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. View of the molecule of (I) showing the atom labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. The hydrogen atoms are omitted for clarity. [Symmetry code: (A) -x, y, 0.5 - z.]
	Fig. 2. The molecular packing of (I). Hydrogen bonds are indicated by dashed lines.

N,N'-Bis(2,6-diethylphenyl)acenaphthylene-1,2-diimine top

Crystal data top

C₃₂H₃₂N₂	Z = 4
M_r = 444.60	F(000) = 952
Monoclinic, C2/c	D_x = 1.140 Mg m⁻³
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 13.5134 (12) Å	θ = 3.7–52.1°
b = 8.6952 (8) Å	µ = 0.07 mm⁻¹
c = 22.3532 (19) Å	T = 185 K
β = 99.413 (1)°	Block, pale yellow
V = 2591.2 (4) Å³	0.25 × 0.24 × 0.21 mm

Data collection top

Bruker SMART APEX CCD diffractometer	2538 independent reflections
Radiation source: fine-focus sealed tube	1842 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.028
ϕ and ω scans	θ_max = 26.0°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2001)	h = −16→14
T_min = 0.984, T_max = 0.986	k = −10→10
7599 measured reflections	l = −27→24

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.151	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.0768P)² + 1.7702P] where P = (F_o² + 2F_c²)/3
2538 reflections	(Δ/σ)_max < 0.001
157 parameters	Δρ_max = 0.42 e Å⁻³
0 restraints	Δρ_min = −0.19 e Å⁻³

Crystal data top

C₃₂H₃₂N₂	V = 2591.2 (4) Å³
M_r = 444.60	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 13.5134 (12) Å	µ = 0.07 mm⁻¹
b = 8.6952 (8) Å	T = 185 K
c = 22.3532 (19) Å	0.25 × 0.24 × 0.21 mm
β = 99.413 (1)°

Data collection top

Bruker SMART APEX CCD diffractometer	2538 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	1842 reflections with I > 2σ(I)
T_min = 0.984, T_max = 0.986	R_int = 0.028
7599 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.053	0 restraints
wR(F²) = 0.151	H-atom parameters constrained
S = 1.02	Δρ_max = 0.42 e Å⁻³
2538 reflections	Δρ_min = −0.19 e Å⁻³
157 parameters

Special details top

Experimental. ¹H NMR (300 MHz, CDCl₃, 298 K) δ (p.p.m.): 1.13 (t, J_H—H = 9.0 Hz, 12H, CH₂CH₃), 2.49 (m, 4H, CH₂CH₃), 2.60 (m, 4H, CH₂CH₃), 6.71 (d, 2H), 7.22 (m, 6H), 7.37 (t, 2H), 7.87 (d, 2H). ¹³C NMR (75 MHz, CDCl₃, 298 K) δ (p.p.m.): 8.74, 19.58, 117.77, 118.81, 121.28, 122.94, 123.68, 124.41, 125.55, 125.86, 135.46, 143.43, 155.61 p.p.m..

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.

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 > σ(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) top

	x	y	z	U_iso*/U_eq
C1	0.48604 (12)	1.10939 (19)	0.30114 (7)	0.0252 (4)
C2	0.47262 (13)	1.1829 (2)	0.35360 (8)	0.0307 (4)
H2	0.4629	1.1260	0.3884	0.037*
C3	0.47366 (14)	1.3456 (2)	0.35439 (9)	0.0358 (5)
H3	0.4654	1.3973	0.3907	0.043*
C4	0.48623 (14)	1.4314 (2)	0.30468 (9)	0.0346 (5)
H4	0.4857	1.5405	0.3070	0.041*
C5	0.5000	1.3587 (3)	0.2500	0.0296 (6)
C6	0.5000	1.1977 (3)	0.2500	0.0259 (5)
C7	0.49133 (12)	0.94636 (19)	0.28284 (7)	0.0244 (4)
C8	0.46314 (14)	0.8115 (2)	0.37023 (8)	0.0290 (4)
C9	0.36277 (14)	0.8239 (2)	0.37853 (8)	0.0353 (5)
C10	0.34091 (17)	0.7996 (3)	0.43645 (10)	0.0531 (6)
H10	0.2735	0.8076	0.4432	0.064*
C11	0.41560 (19)	0.7640 (3)	0.48439 (10)	0.0664 (8)
H11	0.3997	0.7510	0.5239	0.080*
C12	0.51299 (19)	0.7475 (3)	0.47479 (10)	0.0622 (7)
H12	0.5635	0.7204	0.5078	0.075*
C13	0.53893 (15)	0.7696 (3)	0.41798 (9)	0.0426 (5)
C14	0.28009 (15)	0.8561 (3)	0.32569 (9)	0.0446 (5)
H14A	0.2972	0.9501	0.3046	0.054*
H14B	0.2170	0.8764	0.3415	0.054*
C15	0.26253 (17)	0.7249 (3)	0.28009 (10)	0.0542 (6)
H15A	0.3251	0.7018	0.2651	0.081*
H15B	0.2110	0.7550	0.2460	0.081*
H15C	0.2402	0.6334	0.2998	0.081*
C16	0.64667 (17)	0.7500 (3)	0.40762 (10)	0.0571 (7)
H16A	0.6811	0.6753	0.4374	0.068*
H16B	0.6466	0.7075	0.3665	0.068*
C17	0.7033 (2)	0.8979 (4)	0.41362 (14)	0.0786 (9)
H17A	0.6698	0.9720	0.3840	0.118*
H17B	0.7718	0.8800	0.4061	0.118*
H17C	0.7054	0.9388	0.4547	0.118*
N1	0.48669 (11)	0.81965 (16)	0.31083 (6)	0.0273 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0249 (9)	0.0236 (9)	0.0262 (9)	0.0001 (7)	0.0019 (7)	−0.0007 (7)
C2	0.0353 (10)	0.0303 (10)	0.0267 (10)	0.0014 (7)	0.0054 (8)	−0.0028 (8)
C3	0.0419 (11)	0.0314 (11)	0.0338 (11)	0.0024 (8)	0.0058 (8)	−0.0104 (8)
C4	0.0384 (11)	0.0214 (9)	0.0427 (12)	0.0017 (7)	0.0030 (8)	−0.0066 (8)
C5	0.0284 (13)	0.0230 (13)	0.0359 (15)	0.000	0.0006 (11)	0.000
C6	0.0236 (12)	0.0251 (13)	0.0281 (13)	0.000	0.0017 (10)	0.000
C7	0.0247 (8)	0.0239 (9)	0.0240 (9)	0.0000 (7)	0.0024 (7)	−0.0012 (7)
C8	0.0383 (10)	0.0267 (9)	0.0230 (9)	−0.0045 (7)	0.0077 (7)	−0.0004 (7)
C9	0.0373 (11)	0.0386 (11)	0.0308 (10)	−0.0032 (8)	0.0080 (8)	−0.0010 (8)
C10	0.0409 (12)	0.0832 (18)	0.0377 (12)	−0.0097 (11)	0.0141 (10)	−0.0014 (11)
C11	0.0583 (16)	0.117 (2)	0.0267 (12)	−0.0145 (14)	0.0150 (11)	0.0090 (13)
C12	0.0520 (15)	0.104 (2)	0.0286 (12)	−0.0064 (13)	0.0007 (10)	0.0142 (12)
C13	0.0409 (12)	0.0584 (14)	0.0282 (11)	−0.0055 (9)	0.0053 (9)	0.0060 (9)
C14	0.0333 (11)	0.0582 (14)	0.0427 (12)	0.0037 (9)	0.0069 (9)	0.0033 (10)
C15	0.0395 (12)	0.0708 (16)	0.0486 (14)	−0.0116 (11)	−0.0040 (10)	−0.0032 (12)
C16	0.0445 (13)	0.0889 (19)	0.0357 (12)	0.0050 (12)	0.0002 (10)	0.0137 (12)
C17	0.0503 (15)	0.098 (2)	0.086 (2)	−0.0047 (15)	0.0064 (14)	0.0121 (17)
N1	0.0327 (8)	0.0243 (8)	0.0248 (8)	0.0001 (6)	0.0043 (6)	0.0004 (6)

Geometric parameters (Å, º) top

C1—C2	1.373 (2)	C10—C11	1.382 (3)
C1—C6	1.415 (2)	C10—H10	0.9500
C1—C7	1.480 (2)	C11—C12	1.375 (3)
C2—C3	1.414 (3)	C11—H11	0.9500
C2—H2	0.9500	C12—C13	1.385 (3)
C3—C4	1.372 (3)	C12—H12	0.9500
C3—H3	0.9500	C13—C16	1.521 (3)
C4—C5	1.415 (2)	C14—C15	1.522 (3)
C4—H4	0.9500	C14—H14A	0.9900
C5—C6	1.401 (3)	C14—H14B	0.9900
C5—C4ⁱ	1.415 (2)	C15—H15A	0.9800
C6—C1ⁱ	1.415 (2)	C15—H15B	0.9800
C7—N1	1.274 (2)	C15—H15C	0.9800
C7—C7ⁱ	1.524 (3)	C16—C17	1.491 (4)
C8—C13	1.401 (3)	C16—H16A	0.9900
C8—C9	1.403 (3)	C16—H16B	0.9900
C8—N1	1.417 (2)	C17—H17A	0.9800
C9—C10	1.390 (3)	C17—H17B	0.9800
C9—C14	1.513 (3)	C17—H17C	0.9800

C2—C1—C6	119.40 (17)	C10—C11—H11	120.0
C2—C1—C7	134.50 (16)	C11—C12—C13	121.4 (2)
C6—C1—C7	106.10 (15)	C11—C12—H12	119.3
C1—C2—C3	118.29 (17)	C13—C12—H12	119.3
C1—C2—H2	120.9	C12—C13—C8	118.13 (19)
C3—C2—H2	120.9	C12—C13—C16	121.09 (19)
C4—C3—C2	122.42 (17)	C8—C13—C16	120.78 (17)
C4—C3—H3	118.8	C9—C14—C15	113.50 (18)
C2—C3—H3	118.8	C9—C14—H14A	108.9
C3—C4—C5	120.52 (18)	C15—C14—H14A	108.9
C3—C4—H4	119.7	C9—C14—H14B	108.9
C5—C4—H4	119.7	C15—C14—H14B	108.9
C6—C5—C4	116.53 (12)	H14A—C14—H14B	107.7
C6—C5—C4ⁱ	116.53 (12)	C14—C15—H15A	109.5
C4—C5—C4ⁱ	126.9 (2)	C14—C15—H15B	109.5
C5—C6—C1ⁱ	122.85 (11)	H15A—C15—H15B	109.5
C5—C6—C1	122.85 (11)	C14—C15—H15C	109.5
C1ⁱ—C6—C1	114.3 (2)	H15A—C15—H15C	109.5
N1—C7—C1	133.16 (15)	H15B—C15—H15C	109.5
N1—C7—C7ⁱ	120.06 (10)	C17—C16—C13	112.3 (2)
C1—C7—C7ⁱ	106.75 (9)	C17—C16—H16A	109.1
C13—C8—C9	121.42 (16)	C13—C16—H16A	109.1
C13—C8—N1	118.61 (16)	C17—C16—H16B	109.1
C9—C8—N1	119.36 (16)	C13—C16—H16B	109.1
C10—C9—C8	117.95 (18)	H16A—C16—H16B	107.9
C10—C9—C14	120.84 (18)	C16—C17—H17A	109.5
C8—C9—C14	121.16 (16)	C16—C17—H17B	109.5
C11—C10—C9	121.1 (2)	H17A—C17—H17B	109.5
C11—C10—H10	119.4	C16—C17—H17C	109.5
C9—C10—H10	119.4	H17A—C17—H17C	109.5
C12—C11—C10	119.9 (2)	H17B—C17—H17C	109.5
C12—C11—H11	120.0	C7—N1—C8	122.72 (15)

C6—C1—C2—C3	−0.2 (2)	C13—C8—C9—C14	−174.83 (19)
C7—C1—C2—C3	178.84 (18)	N1—C8—C9—C14	−3.9 (3)
C1—C2—C3—C4	0.9 (3)	C8—C9—C10—C11	−0.1 (3)
C2—C3—C4—C5	−0.7 (3)	C14—C9—C10—C11	177.3 (2)
C3—C4—C5—C6	−0.04 (19)	C9—C10—C11—C12	−2.0 (4)
C3—C4—C5—C4ⁱ	179.96 (19)	C10—C11—C12—C13	1.6 (4)
C4—C5—C6—C1ⁱ	−179.32 (11)	C11—C12—C13—C8	0.8 (4)
C4ⁱ—C5—C6—C1ⁱ	0.68 (11)	C11—C12—C13—C16	−179.5 (2)
C4—C5—C6—C1	0.68 (11)	C9—C8—C13—C12	−2.9 (3)
C4ⁱ—C5—C6—C1	−179.32 (11)	N1—C8—C13—C12	−173.9 (2)
C2—C1—C6—C5	−0.55 (17)	C9—C8—C13—C16	177.40 (19)
C7—C1—C6—C5	−179.85 (8)	N1—C8—C13—C16	6.4 (3)
C2—C1—C6—C1ⁱ	179.45 (18)	C10—C9—C14—C15	−110.2 (2)
C7—C1—C6—C1ⁱ	0.15 (8)	C8—C9—C14—C15	67.1 (3)
C2—C1—C7—N1	−1.4 (3)	C12—C13—C16—C17	−93.2 (3)
C6—C1—C7—N1	177.72 (17)	C8—C13—C16—C17	86.5 (3)
C2—C1—C7—C7ⁱ	−179.52 (19)	C1—C7—N1—C8	7.1 (3)
C6—C1—C7—C7ⁱ	−0.4 (2)	C7ⁱ—C7—N1—C8	−175.03 (17)
C13—C8—C9—C10	2.6 (3)	C13—C8—N1—C7	−109.9 (2)
N1—C8—C9—C10	173.49 (18)	C9—C8—N1—C7	78.9 (2)

Symmetry code: (i) −x+1, y, −z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15A···N1	0.98	2.48	3.106 (3)	122
C16—H16B···N1	0.99	2.51	2.862 (3)	101
C4—H4···N1ⁱⁱ	0.95	2.43	3.379 (2)	179

Symmetry code: (ii) x, y+1, z.

Experimental details

Crystal data
Chemical formula	C₃₂H₃₂N₂
M_r	444.60
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	185
a, b, c (Å)	13.5134 (12), 8.6952 (8), 22.3532 (19)
β (°)	99.413 (1)
V (Å³)	2591.2 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.07
Crystal size (mm)	0.25 × 0.24 × 0.21

Data collection
Diffractometer	Bruker SMART APEX CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.984, 0.986
No. of measured, independent and observed [I > 2σ(I)] reflections	7599, 2538, 1842
R_int	0.028
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.053, 0.151, 1.02
No. of reflections	2538
No. of parameters	157
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.42, −0.19

Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···N1ⁱ	0.95	2.43	3.379 (2)	178.6

Symmetry code: (i) x, y+1, z.

Acknowledgements

We thank the National Natural Science Foundation of China (grant Nos. 21004026 and 21074043).

References

Bruker (1998). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Hagar, M., Ragaini, F., Monticelli, E., Caselli, A., Macchi, P. & Casati, N. (2010). Chem. Commun. 46, 6153–6155. Web of Science CSD CrossRef CAS Google Scholar
Kovach, J., Peralta, M., Brennessel, W. W. & Jones, W. D. (2011). J. Mol. Struct. 992, 33–38. Web of Science CSD CrossRef CAS Google Scholar
Li, L.-D., Gomes, C. S. B., Gomes, P. T., Duarte, M. T. & Fan, Z. Q. (2011). Dalton Trans. 40, 3365–3380. Web of Science CSD CrossRef CAS PubMed Google Scholar
Oleinik, I. I., Oleinik, I. V., Ivanchev, S. S. & Tolstikov, G. A. (2005). Russ. J. Org. Chem. 41, 1354–1357. Web of Science CrossRef Google Scholar
Ragaini, F., Gasperini, M., Parma, P., Gallo, E., Casati, N. & Macchi, P. (2006). New J. Chem. 30, 1046–1057. Web of Science CSD CrossRef CAS Google Scholar
Rosa, V., Aviles, T., Aullon, G., Covelo, B. & Lodeiro, C. (2008). Inorg. Chem. 47, 7734–7744. Web of Science CSD CrossRef PubMed CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Small, B. L., Rios, R., Fernandez, E. R. & Carney, M. J. (2007). Organometallics, 26, 1744–1749. Web of Science CrossRef CAS Google Scholar
Zhou, J., Sun, H.-J., Harms, K. & Sundermeyer, J. (2008). Z. Anorg. Allg. Chem. 634, 1517–1521. Web of Science CSD CrossRef CAS Google Scholar