In the crystal structure of the title compound, [Cu(C2N3)2(C12H12N2)]n, the CuII atom adopts a distorted square-pyramidal geometry, the basal plane of which is formed by two N atoms of the bipyridine ligand, one N atom of a bidentate dicyanamide anion and one N atom of a monodentate dicyanamide anion [Cu—N = 1.9760 (15)–2.0157 (15) Å]. The apical position is occupied by an N atom of a bidentate dicyanamide anion, located 2.2468 (16) Å from the Cu atom, thus forming a one-dimensional polymeric chain.
Supporting information
CCDC reference: 182001
Physical measurements and the synthesis of (I) were performed using the methods
described by Riggio et al. (2001). Yield 65%; elemental analysis:
found: C 50.3, H 3.1, N 29.3%; C16H12CuN8 requires: C 50.6, H 3.2, N
29.5%.
H atoms were placed at calculated positions, riding on their carrier atoms. The
methyl H atoms were refined as rigid groups, allowing for rotation around the
C—C bond. Isotropic displacement parameters were coupled to the equivalent
isotropic displacement parameter of the carrier atom.
Data collection: COLLECT (Nonius, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997); data reduction: DENZO; program(s) used to solve structure: SHELXS86 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2001); software used to prepare material for publication: PLATON.
catena-Poly[[dicyanamido(5,5'-dimethyl-2,2'-bipyridine-N,
N')copper(II)]-µ- dicyanamido-N
1:
N5]
top
Crystal data top
[Cu(C2N3)2(C12H12N2)] | F(000) = 772 |
Mr = 379.89 | Quoted _cell_measurement_* data items refer to the initial cell
determination. The cell parameters as reported in _cell_* are based
on the complete data set (29301 reflections wih 0.81 < θ < 27.48 deg). |
Monoclinic, P21/c | Dx = 1.574 Mg m−3 |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 7.5297 (10) Å | Cell parameters from 569 reflections |
b = 23.628 (3) Å | θ = 2.0–25.0° |
c = 9.2916 (10) Å | µ = 1.38 mm−1 |
β = 104.175 (10)° | T = 150 K |
V = 1602.8 (3) Å3 | Block, blue |
Z = 4 | 0.3 × 0.2 × 0.2 mm |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3199 reflections with I > 2σ(I) |
Radiation source: rotating anode | Rint = 0.055 |
Graphite monochromator | θmax = 27.4°, θmin = 1.7° |
Detector resolution: 18.4 pixels mm-1 | h = −9→9 |
ϕ scans, and ω scans with κ offset | k = −30→30 |
29951 measured reflections | l = −12→12 |
3647 independent reflections | |
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)] = 0.027 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.06 | w = 1/[σ2(Fo2) + (0.0312P)2 + 1.15P] where P = (Fo2 + 2Fc2)/3 |
3647 reflections | (Δ/σ)max = 0.001 |
228 parameters | Δρmax = 0.33 e Å−3 |
0 restraints | Δρmin = −0.43 e Å−3 |
Crystal data top
[Cu(C2N3)2(C12H12N2)] | V = 1602.8 (3) Å3 |
Mr = 379.89 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.5297 (10) Å | µ = 1.38 mm−1 |
b = 23.628 (3) Å | T = 150 K |
c = 9.2916 (10) Å | 0.3 × 0.2 × 0.2 mm |
β = 104.175 (10)° | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 3199 reflections with I > 2σ(I) |
29951 measured reflections | Rint = 0.055 |
3647 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.027 | 0 restraints |
wR(F2) = 0.073 | H-atom parameters constrained |
S = 1.06 | Δρmax = 0.33 e Å−3 |
3647 reflections | Δρmin = −0.43 e Å−3 |
228 parameters | |
Special details top
Geometry. Bond distances, angles etc. have been calculated using the rounded
fractional coordinates. All e.s.d.'s are estimated from the variances of the
(full) variance-covariance matrix. The cell e.s.d.'s are taken into account in
the estimation of distances, angles and torsion angles |
Refinement. Refinement on F2 for ALL reflections except those flagged by the user
for potential systematic errors. Weighted R-factors wR
and all goodnesses of fit S are based on F2,
conventional R-factors R are based on F, with F
set to zero for negative F2. The observed criterion of F2 >
σ(F2) is used only for calculating -R-factor-obs
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 | Uiso*/Ueq | |
Cu1 | 0.92344 (3) | 0.11189 (1) | 0.34920 (2) | 0.0170 (1) | |
N1 | 1.1136 (3) | 0.24195 (7) | 0.68048 (19) | 0.0332 (5) | |
N2 | 1.1965 (3) | 0.34243 (8) | 0.6909 (2) | 0.0437 (7) | |
N3 | 0.9725 (2) | 0.18147 (6) | 0.47044 (17) | 0.0234 (5) | |
N4 | 0.4737 (2) | 0.06293 (7) | 0.59410 (16) | 0.0227 (4) | |
N5 | 0.7275 (2) | 0.07599 (7) | 0.47291 (18) | 0.0240 (5) | |
N6 | 1.1490 (2) | 0.07578 (6) | 0.46986 (17) | 0.0217 (5) | |
N11 | 0.74664 (19) | 0.15045 (6) | 0.17939 (16) | 0.0175 (4) | |
N21 | 0.8693 (2) | 0.04704 (6) | 0.20603 (15) | 0.0173 (4) | |
C1 | 1.1558 (3) | 0.29573 (8) | 0.6772 (2) | 0.0239 (6) | |
C2 | 1.0395 (2) | 0.21286 (7) | 0.5632 (2) | 0.0206 (5) | |
C3 | 0.6026 (2) | 0.07021 (7) | 0.52289 (19) | 0.0184 (5) | |
C4 | 1.3033 (2) | 0.07041 (7) | 0.52202 (18) | 0.0170 (5) | |
C12 | 0.6974 (2) | 0.20507 (7) | 0.1739 (2) | 0.0194 (5) | |
C13 | 0.5775 (2) | 0.22947 (7) | 0.0515 (2) | 0.0202 (5) | |
C14 | 0.5050 (3) | 0.19421 (8) | −0.0675 (2) | 0.0251 (6) | |
C15 | 0.5569 (3) | 0.13790 (8) | −0.0644 (2) | 0.0236 (5) | |
C16 | 0.6803 (2) | 0.11705 (7) | 0.06041 (19) | 0.0177 (5) | |
C17 | 0.5322 (3) | 0.29145 (8) | 0.0486 (2) | 0.0259 (6) | |
C22 | 0.9354 (2) | −0.00544 (7) | 0.23325 (19) | 0.0194 (5) | |
C23 | 0.8893 (2) | −0.04947 (7) | 0.1314 (2) | 0.0205 (5) | |
C24 | 0.7712 (3) | −0.03694 (8) | −0.0053 (2) | 0.0219 (5) | |
C25 | 0.7002 (2) | 0.01720 (8) | −0.0337 (2) | 0.0214 (5) | |
C26 | 0.7502 (2) | 0.05849 (7) | 0.07514 (19) | 0.0182 (5) | |
C27 | 0.9657 (3) | −0.10791 (7) | 0.1700 (2) | 0.0264 (6) | |
H12 | 0.74670 | 0.22830 | 0.25770 | 0.0230* | |
H14 | 0.41910 | 0.20880 | −0.15180 | 0.0300* | |
H15 | 0.50850 | 0.11390 | −0.14670 | 0.0280* | |
H17A | 0.54530 | 0.30800 | −0.04500 | 0.0390* | |
H17B | 0.61600 | 0.31050 | 0.13200 | 0.0390* | |
H17C | 0.40590 | 0.29630 | 0.05690 | 0.0390* | |
H22 | 1.01770 | −0.01300 | 0.32640 | 0.0230* | |
H24 | 0.73920 | −0.06550 | −0.07910 | 0.0260* | |
H25 | 0.61840 | 0.02590 | −0.12630 | 0.0260* | |
H27A | 1.06520 | −0.10620 | 0.26040 | 0.0400* | |
H27B | 1.01300 | −0.12270 | 0.08810 | 0.0400* | |
H27C | 0.86860 | −0.13290 | 0.18650 | 0.0400* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.0169 (1) | 0.0151 (1) | 0.0167 (1) | 0.0012 (1) | −0.0003 (1) | −0.0003 (1) |
N1 | 0.0496 (11) | 0.0193 (8) | 0.0231 (8) | −0.0004 (8) | −0.0054 (8) | −0.0013 (6) |
N2 | 0.0753 (15) | 0.0269 (10) | 0.0282 (10) | −0.0143 (10) | 0.0112 (9) | −0.0022 (8) |
N3 | 0.0265 (8) | 0.0185 (8) | 0.0225 (8) | 0.0004 (6) | 0.0009 (6) | 0.0001 (6) |
N4 | 0.0159 (7) | 0.0310 (9) | 0.0193 (7) | −0.0005 (6) | 0.0008 (6) | 0.0022 (6) |
N5 | 0.0201 (8) | 0.0232 (8) | 0.0286 (8) | −0.0016 (6) | 0.0057 (7) | 0.0001 (6) |
N6 | 0.0189 (8) | 0.0225 (8) | 0.0224 (8) | 0.0009 (6) | 0.0028 (6) | 0.0017 (6) |
N11 | 0.0172 (7) | 0.0165 (7) | 0.0175 (7) | −0.0001 (6) | 0.0016 (6) | 0.0010 (6) |
N21 | 0.0177 (7) | 0.0161 (7) | 0.0177 (7) | 0.0006 (6) | 0.0038 (6) | 0.0003 (5) |
C1 | 0.0277 (10) | 0.0242 (10) | 0.0181 (9) | 0.0024 (8) | 0.0022 (7) | −0.0012 (7) |
C2 | 0.0217 (9) | 0.0169 (9) | 0.0216 (9) | 0.0030 (7) | 0.0021 (7) | 0.0031 (7) |
C3 | 0.0188 (8) | 0.0137 (8) | 0.0198 (8) | 0.0006 (7) | −0.0010 (7) | −0.0009 (6) |
C4 | 0.0223 (9) | 0.0134 (8) | 0.0156 (8) | −0.0016 (7) | 0.0053 (7) | 0.0002 (6) |
C12 | 0.0197 (8) | 0.0171 (8) | 0.0208 (8) | 0.0004 (7) | 0.0038 (7) | −0.0006 (7) |
C13 | 0.0197 (9) | 0.0182 (9) | 0.0237 (9) | 0.0019 (7) | 0.0071 (7) | 0.0043 (7) |
C14 | 0.0261 (10) | 0.0263 (10) | 0.0203 (9) | 0.0052 (8) | 0.0008 (7) | 0.0051 (7) |
C15 | 0.0267 (10) | 0.0215 (9) | 0.0196 (9) | 0.0015 (7) | −0.0002 (7) | −0.0005 (7) |
C16 | 0.0181 (8) | 0.0169 (8) | 0.0179 (8) | −0.0007 (7) | 0.0040 (7) | 0.0006 (6) |
C17 | 0.0289 (10) | 0.0204 (9) | 0.0284 (10) | 0.0055 (8) | 0.0068 (8) | 0.0047 (7) |
C22 | 0.0212 (9) | 0.0169 (8) | 0.0194 (8) | 0.0018 (7) | 0.0035 (7) | 0.0026 (7) |
C23 | 0.0235 (9) | 0.0164 (8) | 0.0223 (9) | −0.0005 (7) | 0.0071 (7) | 0.0015 (7) |
C24 | 0.0265 (9) | 0.0182 (9) | 0.0215 (9) | −0.0019 (7) | 0.0066 (7) | −0.0030 (7) |
C25 | 0.0232 (9) | 0.0212 (9) | 0.0182 (8) | −0.0008 (7) | 0.0018 (7) | 0.0007 (7) |
C26 | 0.0175 (8) | 0.0175 (8) | 0.0192 (8) | −0.0006 (7) | 0.0035 (7) | 0.0015 (6) |
C27 | 0.0346 (11) | 0.0174 (9) | 0.0258 (10) | 0.0035 (8) | 0.0049 (8) | 0.0016 (7) |
Geometric parameters (Å, º) top
Cu1—N3 | 1.9760 (15) | C14—C15 | 1.385 (3) |
Cu1—N5 | 2.2468 (16) | C15—C16 | 1.387 (3) |
Cu1—N6 | 1.9841 (16) | C16—C26 | 1.475 (2) |
Cu1—N11 | 2.0157 (15) | C22—C23 | 1.392 (2) |
Cu1—N21 | 2.0045 (14) | C23—C24 | 1.392 (3) |
N1—C1 | 1.312 (3) | C23—C27 | 1.505 (2) |
N1—C2 | 1.294 (2) | C24—C25 | 1.387 (3) |
N2—C1 | 1.144 (3) | C25—C26 | 1.389 (3) |
N3—C2 | 1.155 (2) | C12—H12 | 0.9507 |
N4—C3 | 1.313 (2) | C14—H14 | 0.9500 |
N4—C4i | 1.306 (2) | C15—H15 | 0.9501 |
N5—C3 | 1.154 (2) | C17—H17A | 0.9803 |
N6—C4 | 1.151 (2) | C17—H17B | 0.9807 |
N11—C12 | 1.340 (2) | C17—H17C | 0.9795 |
N11—C16 | 1.351 (2) | C22—H22 | 0.9499 |
N21—C22 | 1.337 (2) | C24—H24 | 0.9501 |
N21—C26 | 1.350 (2) | C25—H25 | 0.9499 |
C12—C13 | 1.392 (2) | C27—H27A | 0.9799 |
C13—C14 | 1.385 (3) | C27—H27B | 0.9802 |
C13—C17 | 1.502 (3) | C27—H27C | 0.9806 |
| | | |
Cu1···N2ii | 3.006 (2) | C25···C23x | 3.512 (2) |
Cu1···C1ii | 3.428 (2) | C25···C25xii | 3.327 (2) |
Cu1···H27Aiii | 3.6099 | C27···C2iii | 3.513 (2) |
N1···C12iv | 3.361 (3) | C1···H14vii | 3.0218 |
N2···Cu1iv | 3.006 (2) | C2···H27Ciii | 2.9443 |
N2···C24v | 3.371 (3) | C2···H17Cviii | 2.7822 |
N3···C1ii | 3.385 (3) | C3···H17Biv | 2.9887 |
N4···C3vi | 3.332 (2) | C3···H17Aiv | 2.9549 |
N6···C22iii | 3.411 (2) | C3···H27Aiii | 2.9271 |
N11···C1ii | 3.338 (3) | C15···H25 | 2.7711 |
N1···H14vii | 2.5647 | C16···H27Bx | 2.9691 |
N1···H17Cviii | 2.8666 | C25···H15 | 2.7684 |
N1···H27Ciii | 2.8467 | C26···H27Bx | 3.0176 |
N2···H27Bv | 2.8080 | H12···N3 | 2.5251 |
N2···H24v | 2.5085 | H12···H17B | 2.3541 |
N3···H12 | 2.5251 | H14···N1xiii | 2.5647 |
N4···H15ix | 2.6477 | H14···C1xiii | 3.0218 |
N4···H25ix | 2.7047 | H15···N4xiv | 2.6477 |
N5···H27Aiii | 2.6818 | H15···C25 | 2.7684 |
N5···H22iii | 2.7606 | H15···H25 | 2.2287 |
N6···H22iii | 2.9195 | H17A···C3ii | 2.9549 |
N6···H22 | 2.5513 | H17B···H12 | 2.3541 |
C1···N11iv | 3.338 (3) | H17B···C3ii | 2.9887 |
C1···Cu1iv | 3.428 (2) | H17C···N1xv | 2.8666 |
C1···N3iv | 3.385 (3) | H17C···C2xv | 2.7822 |
C1···C12iv | 3.444 (3) | H22···N6 | 2.5513 |
C2···C12iv | 3.571 (2) | H22···H27A | 2.3368 |
C2···C27iii | 3.513 (2) | H22···N5iii | 2.7606 |
C3···N4vi | 3.332 (2) | H22···N6iii | 2.9195 |
C3···C4iii | 3.444 (2) | H24···N2xi | 2.5085 |
C3···C17iv | 3.329 (3) | H25···N4xiv | 2.7047 |
C4···C3iii | 3.444 (2) | H25···C15 | 2.7711 |
C4···C22iii | 3.572 (2) | H25···H15 | 2.2287 |
C12···C1ii | 3.444 (3) | H27A···H22 | 2.3368 |
C12···N1ii | 3.361 (3) | H27A···Cu1iii | 3.6099 |
C12···C2ii | 3.571 (2) | H27A···N5iii | 2.6818 |
C17···C3ii | 3.329 (3) | H27A···C3iii | 2.9271 |
C22···N6iii | 3.411 (2) | H27B···N2xi | 2.8080 |
C22···C24x | 3.558 (3) | H27B···C16x | 2.9691 |
C22···C4iii | 3.572 (2) | H27B···C26x | 3.0176 |
C23···C25x | 3.512 (2) | H27C···N1iii | 2.8467 |
C24···C22x | 3.558 (3) | H27C···C2iii | 2.9443 |
C24···N2xi | 3.371 (3) | | |
| | | |
N3—Cu1—N5 | 94.41 (6) | N21—C22—C23 | 123.04 (15) |
N3—Cu1—N6 | 91.20 (6) | C22—C23—C24 | 117.29 (16) |
N3—Cu1—N11 | 93.76 (6) | C22—C23—C27 | 120.44 (16) |
N3—Cu1—N21 | 173.50 (6) | C24—C23—C27 | 122.27 (16) |
N5—Cu1—N6 | 97.30 (6) | C23—C24—C25 | 120.01 (17) |
N5—Cu1—N11 | 100.40 (6) | C24—C25—C26 | 119.09 (16) |
N5—Cu1—N21 | 89.92 (6) | N21—C26—C16 | 114.51 (15) |
N6—Cu1—N11 | 161.18 (6) | N21—C26—C25 | 121.13 (15) |
N6—Cu1—N21 | 93.05 (6) | C16—C26—C25 | 124.36 (16) |
N11—Cu1—N21 | 80.68 (6) | N11—C12—H12 | 118.42 |
C1—N1—C2 | 123.50 (17) | C13—C12—H12 | 118.36 |
Cu1—N3—C2 | 161.09 (14) | C13—C14—H14 | 119.70 |
C3—N4—C4i | 118.59 (15) | C15—C14—H14 | 119.83 |
Cu1—N5—C3 | 162.21 (15) | C14—C15—H15 | 120.40 |
Cu1—N6—C4 | 157.12 (14) | C16—C15—H15 | 120.49 |
Cu1—N11—C12 | 126.05 (12) | C13—C17—H17A | 109.45 |
Cu1—N11—C16 | 114.68 (11) | C13—C17—H17B | 109.51 |
C12—N11—C16 | 119.21 (15) | C13—C17—H17C | 109.46 |
Cu1—N21—C22 | 125.28 (11) | H17A—C17—H17B | 109.44 |
Cu1—N21—C26 | 115.28 (11) | H17A—C17—H17C | 109.50 |
C22—N21—C26 | 119.39 (14) | H17B—C17—H17C | 109.47 |
N1—C1—N2 | 172.5 (2) | N21—C22—H22 | 118.45 |
N1—C2—N3 | 171.53 (19) | C23—C22—H22 | 118.51 |
N4—C3—N5 | 173.61 (19) | C23—C24—H24 | 119.99 |
N4xvi—C4—N6 | 173.99 (18) | C25—C24—H24 | 120.00 |
N11—C12—C13 | 123.22 (16) | C24—C25—H25 | 120.41 |
C12—C13—C14 | 116.93 (16) | C26—C25—H25 | 120.49 |
C12—C13—C17 | 121.15 (16) | C23—C27—H27A | 109.50 |
C14—C13—C17 | 121.91 (16) | C23—C27—H27B | 109.42 |
C13—C14—C15 | 120.47 (17) | C23—C27—H27C | 109.49 |
C14—C15—C16 | 119.11 (17) | H27A—C27—H27B | 109.47 |
N11—C16—C15 | 120.98 (16) | H27A—C27—H27C | 109.49 |
N11—C16—C26 | 114.85 (15) | H27B—C27—H27C | 109.47 |
C15—C16—C26 | 124.17 (16) | | |
| | | |
N3—Cu1—N6—C4 | −59.7 (4) | Cu1—N21—C26—C16 | −0.04 (19) |
N5—Cu1—N6—C4 | −154.3 (4) | Cu1—N21—C26—C25 | −179.69 (12) |
N21—Cu1—N6—C4 | 115.4 (4) | C22—N21—C26—C16 | 177.36 (15) |
N3—Cu1—N11—C12 | −0.39 (15) | C22—N21—C26—C25 | −2.3 (2) |
N3—Cu1—N11—C16 | 177.04 (12) | N11—C12—C13—C17 | −177.64 (17) |
N5—Cu1—N11—C12 | 94.80 (14) | N11—C12—C13—C14 | 1.3 (3) |
N5—Cu1—N11—C16 | −87.77 (12) | C12—C13—C14—C15 | −2.3 (3) |
N21—Cu1—N11—C12 | −177.01 (15) | C17—C13—C14—C15 | 176.62 (19) |
N21—Cu1—N11—C16 | 0.43 (12) | C13—C14—C15—C16 | 1.0 (3) |
N5—Cu1—N21—C22 | −76.87 (14) | C14—C15—C16—C26 | −178.05 (18) |
N5—Cu1—N21—C26 | 100.36 (13) | C14—C15—C16—N11 | 1.5 (3) |
N6—Cu1—N21—C22 | 20.44 (15) | N11—C16—C26—C25 | −179.97 (17) |
N6—Cu1—N21—C26 | −162.34 (12) | C15—C16—C26—N21 | −180.0 (2) |
N11—Cu1—N21—C22 | −177.42 (15) | C15—C16—C26—C25 | −0.3 (3) |
N11—Cu1—N21—C26 | −0.20 (12) | N11—C16—C26—N21 | 0.4 (2) |
Cu1—N11—C12—C13 | 178.44 (12) | N21—C22—C23—C24 | 1.2 (3) |
C16—N11—C12—C13 | 1.1 (2) | N21—C22—C23—C27 | −178.83 (17) |
Cu1—N11—C16—C15 | 179.81 (14) | C22—C23—C24—C25 | −1.9 (3) |
Cu1—N11—C16—C26 | −0.56 (18) | C27—C23—C24—C25 | 178.04 (18) |
C12—N11—C16—C15 | −2.6 (3) | C23—C24—C25—C26 | 0.7 (3) |
C12—N11—C16—C26 | 177.06 (14) | C24—C25—C26—N21 | 1.5 (3) |
Cu1—N21—C22—C23 | 178.07 (12) | C24—C25—C26—C16 | −178.14 (17) |
C26—N21—C22—C23 | 1.0 (2) | | |
Symmetry codes: (i) x−1, y, z; (ii) x, −y+1/2, z−1/2; (iii) −x+2, −y, −z+1; (iv) x, −y+1/2, z+1/2; (v) −x+2, y+1/2, −z+1/2; (vi) −x+1, −y, −z+1; (vii) x+1, y, z+1; (viii) x+1, −y+1/2, z+1/2; (ix) x, y, z+1; (x) −x+2, −y, −z; (xi) −x+2, y−1/2, −z+1/2; (xii) −x+1, −y, −z; (xiii) x−1, y, z−1; (xiv) x, y, z−1; (xv) x−1, −y+1/2, z−1/2; (xvi) x+1, y, z. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12···N3 | 0.95 | 2.53 | 3.066 (2) | 116 |
C14—H14···N1xiii | 0.95 | 2.56 | 3.473 (3) | 160 |
C22—H22···N6 | 0.95 | 2.55 | 3.061 (2) | 114 |
C24—H24···N2xi | 0.95 | 2.51 | 3.371 (3) | 151 |
Symmetry codes: (xi) −x+2, y−1/2, −z+1/2; (xiii) x−1, y, z−1. |
Experimental details
Crystal data |
Chemical formula | [Cu(C2N3)2(C12H12N2)] |
Mr | 379.89 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 150 |
a, b, c (Å) | 7.5297 (10), 23.628 (3), 9.2916 (10) |
β (°) | 104.175 (10) |
V (Å3) | 1602.8 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 1.38 |
Crystal size (mm) | 0.3 × 0.2 × 0.2 |
|
Data collection |
Diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 29951, 3647, 3199 |
Rint | 0.055 |
(sin θ/λ)max (Å−1) | 0.648 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.027, 0.073, 1.06 |
No. of reflections | 3647 |
No. of parameters | 228 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.33, −0.43 |
Selected geometric parameters (Å, º) topCu1—N3 | 1.9760 (15) | Cu1—N11 | 2.0157 (15) |
Cu1—N5 | 2.2468 (16) | Cu1—N21 | 2.0045 (14) |
Cu1—N6 | 1.9841 (16) | | |
| | | |
N3—Cu1—N5 | 94.41 (6) | N5—Cu1—N11 | 100.40 (6) |
N3—Cu1—N6 | 91.20 (6) | N5—Cu1—N21 | 89.92 (6) |
N3—Cu1—N11 | 93.76 (6) | N6—Cu1—N11 | 161.18 (6) |
N3—Cu1—N21 | 173.50 (6) | N6—Cu1—N21 | 93.05 (6) |
N5—Cu1—N6 | 97.30 (6) | N11—Cu1—N21 | 80.68 (6) |
Dicyanamide complexes have attracted much interest in recent years as a new class of magnetic materials, especially in the form of MII[N(CN)2]2 (M is Ni, Co, Cu or Zn) (Batten et al., 1998; Jensen, Batten, Fallon, Moubaraki et al., 1999; Jensen et al., 2001; Kohout et al., 2000; Manson et al., 1998, 1999; Miller & Manson, 2001). The X-ray structures of a number of compounds containing the dicyanamide anion and copper(II) have been reported (Potočňák et al., 2001; Riggio et al., 2001; Martín et al., 2001). Dicyanamide itself is a most interesting anionic bridging ligand. It can act as a monodentate, bidentate (with two distinct types of binding), or even tridentate ligand (Mroziński et al., 1997; Escuer et al., 2000). However, X-ray structures of polymeric compounds with CuII and dicyanamide with the general formula [CuII{N(CN)2}2(L)y]n (y = 1 or 2 and L is a coordinating organic molecule) are very rare. Currently, only six crystal structures of this type of compound have been reported, in which four different types of polymeric network can be discerned.
A one-dimensional network (type A, Fig. 2) is found in [CuII{N(CN)2}2(2-aminopyrimidine)2]n (van Albada et al., 2000). Dicyanamide and CuII cations form an infinite chain with two bridging dicyanamide anions between each pair of CuII cations. β-[CuII{N(CN)2}2(pyrazine)2]n (Jensen, Batten, Fallon, Hockless et al., 1999) forms a two-dimensional network (type B, Fig. 2), in which one of the base directions is the structural element found in the previous compound, and the second base direction is formed by the pyrazine ligand, which forms a bridge between two adjacent Cu[N(CN)2]2 chains. The compounds α-[CuII{N(CN)2}2(pyrazine)2]n (Jensen, Batten, Fallon, Hockless et al., 1999), [CuII{N(CN)2}2(pyrimidine)2]n (Riggio et al., 2001) and [CuII{N(CN)2}2(bipyrimidine)]n (Martín et al., 2001) form three-dimensional networks (type C, Fig. 2). This type of network consists of two-dimensional Cu[N(CN)2]2 sheets, with a single dicyanamide anion between each pair of CuII cations. The third dimension is obtained by linking these copper-dicyanimide sheets through the organic ligand, in a similar way to that found in the two-dimensional networks of type B. The fourth network type (type D, Fig. 2) is found for the compounds [CuII{N(CN)2}2(1,10-phenanthroline)2]n (Wang et al., 2000) and [CuII{N(CN)2}2(3-hydroxopyridine)2]n (van Albada et al., 2001). These compounds form an infinite one-dimensional chain, with only one bridging dicyanamide anion between each pair of CuII cations. The second dicyanamide is monodendate and the organic ligand co-ordinates only to a single CuII cation. The title compound, (I), is a new example of a type D network. \sch
The geometry around the CuII ion in (I) is distorted square pyramidal. The basal plane is formed by the two N atoms of the 5,5'-dimethyl-2,2'-bipyridine ligand (N11, N21), one N atom of the monodentate dicyanamide anion (N3) and one terminal N atom of the bridging dicyanamide anion (N6). The Cu—N distances vary from 1.9760 (15) to 2.0157 (15) Å. The apical position is occupied by the other terminal N atom of the bridging dicyanamide anion (N5) at a distance of 2.2468 (16) Å from the CuII ion. The distortion of the square pyramid can be described by the parameter τ (τ describes the relative amount of trigonality; τ = 0 for a square pyramid and τ = 1 for a trigonal bipyramid; Addison et al., 1984). For complex (I), τ = 0.21.
The Cu···Cu distance along the polymeric chain of (I) is 7.5297 (10) Å, i.e. equal to the length of the a axis. The Cu-dicyanamide-Cu distances reported for the complexes discussed above all lie in the range 7.39–7.71 Å, with the exception of the distances observed in the α-form of the pyrazine complex (Jensen, Batten, Fallon, Hockless et al., 1999), belonging to network type C, which are in the range 8.64–8.83 Å. On the basis of the Cu-dicyanamide-Cu distances, no clear distinction can be made between Cu-complexes of different network types.
In the complexes with network type D, [CuII{N(CN)2}2(3-hydroxopyridine)2]n (van Albada et al., 2001) and [CuII{N(CN)2}2(1,10-phenanthroline)2]n (Wang et al., 2000), there is a close contact between the CuII ions and the remaining terminal N atoms of the monodentate dicyanamide anions. These N atoms occupy the second apical site of the CuII ions, at a distance from the CuII of 2.97 and 2.82 Å for the hydroxopyridine and the phenanthroline complexes, respectively. In (I), the second apical site of the CuII ion is occupied by the remaining terminal N atom (N2), located at a distance of 3.006 (2) Å from Cu1. Although rather long for an interaction, this distance is still 0.86 Å shorter then the sum of the van der Waals radii. The relatively high displacement parameters of N2 indicate that there is only a weak interaction with Cu1.
If these additional contacts are considered as true interactions, the description of the polymeric structures of type D complexes has to be expanded. In the hydroxopyridine complex, the dicyanamide anions have orientations similar to those found in networks of type A (the aminopyridine complex), meaning that N2 is in close contact with the neighbouring CuII ion within the infinite one-dimensional network. In (I), atom N2 has a close contact with a CuII ion of a neighbouring Cu[N(CN)2]2 chain, resulting in a two-dimensional network of CuII cations and dicyanamide anions (Fig. 3), similar to the sheets found in networks of type C. In contrast with those networks, however, the dimethylbipyridine ligand in (I) interacts with only one CuII ion, so the two-dimensional networks are not linked to each other and a three-dimensional network is not formed. In the phenanthroline complex, a two-dimensional network is found, related to the one present in (I). In this network, however, not all dicyanamide links between CuII ion pairs are present, while others are doubled, i.e. are formed by two bridging anions.
The crystal lattice of (I) is further stabilized by weak π···π interactions. The pyridine ring containing N21 is stacked on the inversion images generated by the symmetry operation (2 - x, -y, -z). The distance between the geometric centres of the rings is 3.6749 (11) Å.
The ligand field spectrum of the CuII derivative shows a broad d-d transition band centred around 14.5 × 103 cm-1, with a shoulder at the low-energy side. The characteristic IR vibrations for the dicyanamide anion are the νs + νas(CN) vibrations. These vibrations are found as a strong band at 2289 cm-1, two medium strong bands at 2248 and 2229 cm-1 and a broad very strong band at 2160 cm-1, with a shoulder at 2175 cm-1. The EPR (please define EPR) spectrum, measured on (I) as a polycrystalline powder, shows an axial S = 1/2 spectrum with g\perp = 2.09 and g\parallel (very weak broad) = 2.26, values typical for CuII. These values are in agreement with observations made earlier by Riggio et al. (2001).
The magnetic susceptibility of powdered samples of (I) was measured from 5 to 300 K. The plot of µeff versus temperature gives hardly any changes at lower temperatures and stays constant at a value of 1.70–1.85 µB down to 5 K, which is close to the spin-only value for CuII. Given the fact that the magnetic (dx2-y2) orbitals of neighbouring CuII ions are mutually orthogonal (the four short Cu—N bonds are within the same planes) and the other Cu···Cu distances are large (5.96 Å), one would not expect any significant interactions. So, in the present case, at best a very weak antiferromagnetism is present (J > -1 cm-1), as down to 5 K no maximum in χ is observed.