trans-Bis{2-[(3-cyclo­hexyl­amino­propylimino)­methyl]­phenolato}di­thio­cyanatonickel(II)

In the title compound, [Ni(C₁₆H₂₃N₂O)₂(NCS)₂], a mononuclear complex possessing C_i symmetry, the Ni^II atom is coordinated by six atoms from two Schiff bases and two thio­cyanate anions. In the crystal structure, mol­ecules are held together by intermolecular N—H...S hydrogen bonds, which link the mol­ecules along the b axis to form one-dimensional chains.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.045
• wR factor = 0.145
• Data-to-parameter ratio = 14.8

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT761_ALERT_1_A CIF Contains no X-H Bonds ......................          ?
PLAT762_ALERT_1_A CIF Contains no X-Y-H or H-Y-H Angles ..........          ?

Alert level C
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT242_ALERT_2_C Check Low    U(eq) as Compared to Neighbors ....        C11
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          7

   2 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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S1. Comment

The title compound, (I), is a discrete electronically neutral centrosymmetric mononuclear nickel(II) complex (Fig. 1). The central Ni atom is in an octahedral geometry and coordinates to two Schiff base ligands and two thiocyanate groups. The Schiff base acts as a bidentate ligand and ligates to atom Ni1 through the phenolate O and imine N atoms. The thiocyanate anion is a monodentate ligand and coordinates to the metal via the N atom. The three diagonal angles for the nickel(II) octahedron are all 180°, and all the other angles around atom Ni1 are close to 90°, varying from 87.27 (14) to 92.73 (14)°, which indicates a slightly distorted octahedral geometry around the Ni atom. The Ni1—O1 (phenolate O atom) bond length of 2.030 (3) Å is comparable to the value of 2.013 (5) Å observed in a salicylaldehyde nickel(II) complex (Stewart et al., 1961). The Ni1—N1 bond distance of 2.078 (3) Å (imine N atom) is close to the value of 2.068 (3) Å observed in the complex [Ni₂(tp)(pren)₄(Him)₂](ClO₄)₂ (Zhu et al., 2001), [where tp is terephthalate, pren is 1,3-diaminopropane and Him is imidazole]. The NCS angle of 178.7 (4)° in the coordinated thiocyanate anions is comparable to that observed in other nickel(II) complexes with NCS⁻ anions.

In the crystal structure, the molecules are connected by intermolecular N2—H2···S1ⁱ hydrogen bonds (see Fig. 2 and Table 1) to form columns parallel to the b axis (Fig. 3). As expected, the cyclohexyl groups in the complex adopt chair conformations to minimize steric effects.

S2. Experimental

N-cyclohexyl-1,3-diaminopropane and salicylaldehyde were available commercially and were used without further purification. N-cyclohexyl-1,3-diaminopropane (2.0 mmol, 312 mg) and salicylaldehyde (2.0 mmol, 244 mg) were dissoved in methanol (10 ml). The mixture was stirred for ca 30 min to obtain a clear yellow solution of L (2.0 mmol), where L is 2-[(3-cyclohexylaminopropylimino)methyl]phenol. To the solution of L was added a solution of Ni(NCS)₂ (1.0 mmol, 175 mg) in pyridine, with stirring. After keeping the resulting solution in air for 5 d, petal-like green crystals were formed on slow evaporation of the solvents. The crystals were isolated, washed with methanol three times and dried in a vacuum desiccator using CaCl₂ (yield 52%). Analysis found: C 59.06, H 6.76, N 12.10%; calculated for C₃₄H₄₆N₆NiO₂S₂: C 58.88, H 6.68, N 12.12%.

S3. Refinement

The amino H atom was located from a difference Fourier synthesis and refined isotropically. All the C—H atoms were placed in idealized positions and constrained to ride on their parent atoms, with C—H distances of 0.97 Å and U_iso(H) values equal to 1.2U_eq of the parent C atom.

Computing details

Data collection: SMART (Siemens, 1996); cell refinement: SMART; data reduction: SHELXTL (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The structure of (I), showing 50% probability displacement ellipsoids and the atom-numbering scheme. [Symmetry code: (A) 1 − x, 1 − y, −z.]
	Fig. 2. The crystal packing of (I), showing the N—H···S hydrogen- bonding interactions as dashed lines.
	Fig. 3. The crystal packing of (I), viewed along the b axis. H atoms have been omitted for clarity.

trans-Bis{2-[(3- cyclohexylaminopropylimino)methyl]phenolato}dithiocyanatonickel(II)

Crystal data

[Ni(C16H23N2O)2(NCS)2]	F(000) = 736
Mr = 693.60	Dx = 1.318 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.906 (7) Å	Cell parameters from 1432 reflections
b = 7.796 (5) Å	θ = 2.6–18.5°
c = 20.721 (13) Å	µ = 0.71 mm^−1
β = 97.131 (11)°	T = 298 K
V = 1748.0 (18) Å^3	Petal-like, green
Z = 2	0.24 × 0.22 × 0.17 mm

Data collection

Bruker SMART CCD area-detector diffractometer	3085 independent reflections
Radiation source: fine-focus sealed tube	1857 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.050
ϕ and ω scans	θmax = 25.0°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −12→12
Tmin = 0.847, Tmax = 0.888	k = −9→9
8924 measured reflections	l = −14→24

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.145	H atoms treated by a mixture of independent and constrained refinement
S = 0.94	w = 1/[σ^2(Fo^2) + (0.0718P)^2] where P = (Fo^2 + 2Fc^2)/3
3085 reflections	(Δ/σ)max < 0.001
209 parameters	Δρmax = 0.48 e Å^−3
2 restraints	Δρmin = −0.50 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Ni1	0.5000	0.5000	0.0000	0.0447 (3)
N1	0.4030 (3)	0.3537 (4)	−0.07313 (17)	0.0460 (9)
N2	0.2117 (3)	0.2458 (4)	0.05256 (17)	0.0461 (9)
N3	0.6557 (3)	0.3439 (5)	−0.01038 (19)	0.0588 (10)
O1	0.5526 (2)	0.6577 (4)	−0.06953 (14)	0.0509 (7)
S1	0.82244 (11)	0.17350 (15)	−0.08026 (6)	0.0614 (4)
C1	0.3780 (4)	0.4052 (6)	−0.1316 (2)	0.0530 (12)
H1	0.3403	0.3260	−0.1612	0.064*
C2	0.4016 (4)	0.5736 (6)	−0.1573 (2)	0.0498 (11)
C3	0.4856 (4)	0.6917 (6)	−0.1253 (2)	0.0480 (11)
C4	0.4996 (4)	0.8487 (6)	−0.1568 (2)	0.0551 (12)
H4	0.5540	0.9297	−0.1366	0.066*
C5	0.4361 (4)	0.8863 (7)	−0.2160 (2)	0.0622 (13)
H5	0.4464	0.9926	−0.2350	0.075*
C6	0.3560 (5)	0.7666 (8)	−0.2480 (2)	0.0692 (14)
H6	0.3136	0.7908	−0.2887	0.083*
C7	0.3408 (4)	0.6137 (7)	−0.2187 (2)	0.0595 (13)
H7	0.2881	0.5328	−0.2403	0.071*
C8	0.3659 (4)	0.1756 (6)	−0.0604 (2)	0.0605 (13)
H8A	0.4064	0.1396	−0.0182	0.073*
H8B	0.3933	0.1004	−0.0930	0.073*
C9	0.2258 (4)	0.1577 (6)	−0.0615 (2)	0.0642 (13)
H9A	0.1873	0.1765	−0.1056	0.077*
H9B	0.2078	0.0406	−0.0498	0.077*
C10	0.1669 (4)	0.2766 (6)	−0.0172 (2)	0.0575 (12)
H10A	0.1847	0.3943	−0.0281	0.069*
H10B	0.0779	0.2614	−0.0243	0.069*
C11	0.1355 (4)	0.3315 (5)	0.0996 (2)	0.0471 (11)
H11	0.1250	0.4525	0.0874	0.057*
C12	0.0090 (4)	0.2500 (8)	0.0962 (3)	0.0839 (17)
H12A	0.0178	0.1275	0.1038	0.101*
H12B	−0.0355	0.2669	0.0532	0.101*
C13	−0.0644 (5)	0.3289 (9)	0.1471 (3)	0.095 (2)
H13A	−0.0819	0.4480	0.1360	0.114*
H13B	−0.1427	0.2693	0.1460	0.114*
C14	0.0020 (5)	0.3198 (7)	0.2135 (3)	0.0792 (16)
H14A	0.0109	0.2007	0.2269	0.095*
H14B	−0.0455	0.3784	0.2434	0.095*
C15	0.1277 (5)	0.4011 (8)	0.2162 (3)	0.0857 (17)
H15A	0.1720	0.3861	0.2594	0.103*
H15B	0.1184	0.5232	0.2080	0.103*
C16	0.2022 (4)	0.3223 (7)	0.1664 (2)	0.0703 (14)
H16A	0.2804	0.3823	0.1676	0.084*
H16B	0.2197	0.2033	0.1776	0.084*
C17	0.7234 (4)	0.2723 (5)	−0.0392 (2)	0.0453 (10)
H2	0.211 (3)	0.1303 (14)	0.0621 (14)	0.038 (11)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0365 (4)	0.0509 (5)	0.0478 (5)	−0.0032 (4)	0.0103 (3)	−0.0042 (4)
N1	0.0376 (19)	0.053 (2)	0.049 (2)	−0.0046 (16)	0.0141 (18)	−0.0104 (19)
N2	0.048 (2)	0.038 (2)	0.054 (2)	0.0018 (17)	0.0097 (18)	−0.0014 (18)
N3	0.046 (2)	0.062 (3)	0.069 (3)	0.0049 (19)	0.012 (2)	−0.011 (2)
O1	0.0401 (16)	0.0641 (19)	0.0484 (18)	−0.0103 (14)	0.0050 (15)	0.0011 (15)
S1	0.0578 (7)	0.0506 (7)	0.0789 (9)	0.0024 (6)	0.0211 (7)	−0.0028 (6)
C1	0.041 (3)	0.067 (3)	0.052 (3)	−0.007 (2)	0.009 (2)	−0.020 (3)
C2	0.038 (2)	0.068 (3)	0.044 (3)	−0.001 (2)	0.011 (2)	−0.008 (2)
C3	0.036 (2)	0.064 (3)	0.048 (3)	0.004 (2)	0.019 (2)	−0.004 (2)
C4	0.041 (3)	0.064 (3)	0.061 (3)	0.002 (2)	0.011 (2)	0.004 (3)
C5	0.054 (3)	0.073 (4)	0.061 (3)	0.012 (3)	0.015 (3)	0.013 (3)
C6	0.063 (3)	0.095 (4)	0.048 (3)	0.016 (3)	0.005 (3)	0.005 (3)
C7	0.049 (3)	0.077 (4)	0.052 (3)	0.003 (2)	0.009 (2)	−0.008 (3)
C8	0.068 (3)	0.052 (3)	0.064 (3)	−0.006 (2)	0.019 (3)	−0.015 (2)
C9	0.067 (3)	0.070 (3)	0.057 (3)	−0.025 (3)	0.010 (3)	−0.006 (3)
C10	0.041 (2)	0.073 (3)	0.059 (3)	−0.009 (2)	0.004 (2)	0.005 (3)
C11	0.042 (2)	0.041 (2)	0.060 (3)	0.0028 (19)	0.015 (2)	0.000 (2)
C12	0.037 (3)	0.128 (5)	0.089 (4)	−0.010 (3)	0.019 (3)	−0.026 (4)
C13	0.048 (3)	0.135 (5)	0.109 (5)	−0.007 (3)	0.034 (4)	−0.027 (4)
C14	0.077 (4)	0.078 (4)	0.090 (4)	−0.002 (3)	0.043 (4)	0.000 (3)
C15	0.066 (3)	0.125 (5)	0.069 (4)	0.004 (3)	0.019 (3)	−0.020 (4)
C16	0.047 (3)	0.098 (4)	0.066 (3)	0.005 (3)	0.010 (3)	−0.016 (3)
C17	0.040 (2)	0.042 (2)	0.053 (3)	−0.006 (2)	0.000 (2)	0.002 (2)

Geometric parameters (Å, º)

Ni1—O1	2.030 (3)	C2—C7	1.395 (6)
Ni1—O1^i	2.030 (3)	C2—C3	1.405 (6)
Ni1—N1	2.078 (3)	C3—C4	1.403 (6)
Ni1—N1^i	2.078 (3)	C4—C5	1.364 (6)
Ni1—N3^i	2.121 (4)	C5—C6	1.389 (7)
Ni1—N3	2.121 (4)	C6—C7	1.358 (6)
N1—C1	1.273 (5)	C8—C9	1.531 (6)
N1—C8	1.479 (5)	C9—C10	1.503 (6)
N2—C10	1.488 (5)	C11—C16	1.482 (6)
N2—C11	1.512 (5)	C11—C12	1.513 (6)
N3—C17	1.150 (5)	C12—C13	1.529 (6)
O1—C3	1.316 (5)	C13—C14	1.475 (7)
S1—C17	1.648 (5)	C14—C15	1.505 (7)
C1—C2	1.452 (7)	C15—C16	1.520 (6)
O1—Ni1—O1^i	180.00 (11)	C7—C2—C3	119.4 (4)
O1—Ni1—N1	88.74 (13)	C7—C2—C1	116.8 (4)
O1^i—Ni1—N1	91.26 (13)	C3—C2—C1	123.7 (4)
O1—Ni1—N1^i	91.26 (13)	O1—C3—C4	120.2 (4)
O1^i—Ni1—N1^i	88.74 (13)	O1—C3—C2	122.7 (4)
N1—Ni1—N1^i	180.00 (15)	C4—C3—C2	117.1 (4)
O1—Ni1—N3^i	91.43 (13)	C5—C4—C3	122.2 (5)
O1^i—Ni1—N3^i	88.57 (13)	C4—C5—C6	120.3 (5)
N1—Ni1—N3^i	92.73 (14)	C7—C6—C5	118.7 (5)
N1^i—Ni1—N3^i	87.27 (14)	C6—C7—C2	122.3 (5)
O1—Ni1—N3	88.57 (13)	N1—C8—C9	112.2 (4)
O1^i—Ni1—N3	91.43 (13)	C10—C9—C8	115.9 (4)
N1—Ni1—N3	87.27 (14)	N2—C10—C9	112.3 (4)
N1^i—Ni1—N3	92.73 (14)	C16—C11—N2	109.6 (3)
N3^i—Ni1—N3	180.0 (2)	C16—C11—C12	111.2 (4)
C1—N1—C8	115.8 (4)	N2—C11—C12	110.8 (3)
C1—N1—Ni1	123.4 (3)	C11—C12—C13	110.6 (4)
C8—N1—Ni1	120.7 (3)	C14—C13—C12	112.7 (5)
C10—N2—C11	114.5 (3)	C13—C14—C15	110.7 (4)
C17—N3—Ni1	154.8 (4)	C14—C15—C16	111.4 (4)
C3—O1—Ni1	124.8 (3)	C11—C16—C15	111.9 (4)
N1—C1—C2	127.4 (4)	N3—C17—S1	178.7 (4)

Symmetry code: (i) −x+1, −y+1, −z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···S1^ii	0.92 (1)	2.43 (1)	3.348 (4)	171 (3)

Symmetry code: (ii) −x+1, −y, −z.