Poly[μ-cyano-μ-pyrazine-nickel(I)]

The title compound, [Ni(CN)(C₄H₄N₂)]_n, was prepared by the hydro­thermal reaction of NiCl₂, KCN and pyrazine. The Ni^II atoms are linked via cyanide ligands into a zigzag [NC–Ni–NC]_∞ chain running parallel to [010]. These chains are further connected into a three-dimensional network by bridging pyrazine ligands, which have inversion symmetry. The coordination geometry around the Ni^II atom is distorted tetra­hedral, with one N and one C atom from the cyanide and two N atoms from the pyrazine ligands.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.009 Å
• R factor = 0.040
• wR factor = 0.116
• Data-to-parameter ratio = 11.3

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT213_ALERT_2_B Atom C5      has ADP max/min Ratio .............       4.90 oblat

Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.94
PLAT164_ALERT_4_C Nr. of Refined C-H H-Atoms in Heavy-At Struct...          4
PLAT241_ALERT_2_C Check High      Ueq as Compared to Neighbors for         N3
PLAT341_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          9
PLAT764_ALERT_4_C Overcomplete CIF Bond List Detected (Rep/Expd) .       1.27 Ratio

Alert level G
ABSTM02_ALERT_3_G  When printed, the submitted absorption T values will be
            replaced by the scaled T values. Since the ratio of scaled T's
            is identical to the ratio of reported T values, the scaling
            does not imply a change to the absorption corrections used in
            the study.
            Ratio of Tmax expected/reported      0.939
            Tmax scaled      0.553 Tmin scaled      0.553

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

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

---

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXL97.

Poly[µ-cyano-µ-pyrazine-nickel(II)]

Crystal data

[Ni(CN)(C4H4N2)]	F(000) = 332
Mr = 164.82	Dx = 1.730 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1110 reflections
a = 6.193 (3) Å	θ = 2.9–25.0°
b = 9.152 (4) Å	µ = 2.96 mm^−1
c = 11.167 (5) Å	T = 298 K
β = 90.908 (5)°	Block, green
V = 632.9 (5) Å^3	0.20 × 0.20 × 0.20 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	1110 independent reflections
Radiation source: fine-focus sealed tube	803 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
φ and ω scans	θmax = 25.0°, θmin = 2.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −6→7
Tmin = 0.589, Tmax = 0.589	k = −10→9
3130 measured reflections	l = −13→12

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.116	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.052P)^2 + 1.4011P] where P = (Fo^2 + 2Fc^2)/3
1110 reflections	(Δ/σ)max = 0.009
98 parameters	Δρmax = 0.53 e Å^−3
4 restraints	Δρmin = −0.34 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	0.34379 (11)	0.53169 (8)	0.25378 (6)	0.0453 (3)
N1	0.1207 (8)	0.5209 (6)	0.1045 (4)	0.0539 (12)
N2	0.1255 (8)	0.5073 (5)	0.3980 (4)	0.0510 (12)
N3	0.4725 (8)	0.7275 (8)	0.2504 (4)	0.0706 (17)
C1	0.1828 (10)	0.5718 (8)	0.0000 (6)	0.0668 (19)
C2	−0.0655 (10)	0.4494 (8)	0.1027 (6)	0.0629 (18)
C3	−0.0618 (10)	0.5781 (8)	0.4071 (6)	0.0619 (17)
C4	0.1843 (10)	0.4293 (8)	0.4934 (6)	0.0604 (17)
C5	0.5375 (8)	0.8401 (5)	0.2479 (5)	0.0392 (13)
H3	−0.101 (9)	0.635 (6)	0.341 (4)	0.067 (19)*
H1	0.304 (9)	0.640 (7)	−0.005 (6)	0.08 (2)*
H2	−0.144 (9)	0.423 (7)	0.175 (4)	0.067 (18)*
H4	0.307 (9)	0.360 (7)	0.484 (6)	0.09 (2)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ni1	0.0463 (4)	0.0379 (4)	0.0517 (5)	−0.0015 (3)	0.0037 (3)	0.0040 (3)
N1	0.047 (3)	0.061 (3)	0.053 (3)	−0.013 (2)	−0.007 (2)	0.009 (2)
N2	0.052 (3)	0.052 (3)	0.049 (3)	0.006 (2)	0.007 (2)	0.012 (2)
N3	0.047 (3)	0.110 (5)	0.054 (3)	0.023 (3)	0.003 (2)	−0.003 (3)
C1	0.055 (4)	0.086 (6)	0.059 (4)	−0.026 (4)	−0.005 (3)	0.015 (4)
C2	0.057 (4)	0.082 (5)	0.050 (4)	−0.014 (3)	0.003 (3)	0.010 (3)
C3	0.060 (4)	0.073 (5)	0.053 (4)	0.013 (3)	0.008 (3)	0.016 (3)
C4	0.055 (4)	0.068 (5)	0.059 (4)	0.016 (3)	0.014 (3)	0.015 (3)
C5	0.050 (3)	0.007 (2)	0.061 (3)	−0.014 (2)	0.007 (2)	0.001 (2)

Geometric parameters (Å, º)

Ni1—C5^i	1.901 (5)	C1—C2^ii	1.362 (9)
Ni1—N3	1.962 (7)	C1—H1	0.98 (4)
Ni1—N2	2.131 (5)	C2—C1^ii	1.362 (9)
Ni1—N1	2.150 (5)	C2—H2	0.98 (4)
N1—C1	1.320 (8)	C3—C4^iii	1.357 (9)
N1—C2	1.325 (7)	C3—H3	0.93 (4)
N2—C4	1.328 (8)	C4—C3^iii	1.357 (9)
N2—C3	1.334 (8)	C4—H4	1.00 (4)
N3—C5	1.107 (7)	C5—Ni1^iv	1.901 (5)
C5^i—Ni1—N3	133.2 (2)	N1—C1—C2^ii	122.4 (6)
C5^i—Ni1—N2	99.3 (2)	N1—C1—H1	120 (4)
N3—Ni1—N2	111.90 (19)	C2^ii—C1—H1	116 (4)
C5^i—Ni1—N1	101.2 (2)	N1—C2—C1^ii	122.4 (6)
N3—Ni1—N1	106.47 (19)	N1—C2—H2	124 (4)
N2—Ni1—N1	99.99 (19)	C1^ii—C2—H2	113 (3)
C1—N1—C2	115.2 (5)	N2—C3—C4^iii	122.4 (6)
C1—N1—Ni1	118.5 (4)	N2—C3—H3	115 (4)
C2—N1—Ni1	125.6 (4)	C4^iii—C3—H3	122 (4)
C4—N2—C3	115.3 (5)	N2—C4—C3^iii	122.2 (6)
C4—N2—Ni1	119.6 (4)	N2—C4—H4	117 (4)
C3—N2—Ni1	124.7 (4)	C3^iii—C4—H4	119 (4)
C5—N3—Ni1	177.3 (5)	N3—C5—Ni1^iv	178.3 (5)

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