(2,2′-Bi­pyridine-κ²N,N′)(dichromato-κO)copper(II)

The title compound, [Cu(Cr₂O₇)(C₁₀H₈N₂)₂], a new mixed-metal molecular compound, contains isolated molecular units, each comprised of one Cu^II atom coordinated to two 2,2′-bi­pyridine ligands and also to an oxy­gen vertex of a dichromate anion. The Cu^II atom has an approximate trigonal–bipyramidal geometry, which is consistent with previous studies. Both enantiomers of the chiral complex mol­ecule are present and are related by inversion centers. In a reported pyridine analogue, achiral [Cu(Cr₂O₇)(pyridine)₄] chains pack in the non-centrosymmetric space group Pna2₁. Differences in the organic ligands influence the chirality and dimensionality of the Cu—Cr₂O₇ bonding.

Computing details

Data collection: SMART-NT (Siemens, 1996); cell refinement: SAINT-Plus (Siemens, 1996); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS (Dowty, 1999).

bis(2,2'-bipyridine)(dichromate)copper(II)

Crystal data

[Cu(C10H8N2)2(Cr2O7)]	Z = 2
Mr = 591.91	F(000) = 594
Triclinic, P1	Dx = 1.811 Mg m^−3 Dm = 1.840 (3) Mg m^−3 Dm measured by flotation pycnometry
a = 7.7958 (11) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.9319 (14) Å	Cell parameters from 5015 reflections
c = 14.849 (2) Å	θ = 4–28°
α = 74.673 (2)°	µ = 2.01 mm^−1
β = 81.960 (2)°	T = 153 K
γ = 79.617 (2)°	Block, translucent dark green
V = 1085.5 (3) Å^3	0.16 × 0.12 × 0.09 mm

Data collection

Bruker AXS diffractometer	5015 independent reflections
Radiation source: fine-focus sealed tube	4227 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
CCD scans	θmax = 28.3°, θmin = 1.4°
Absorption correction: empirical (using intensity measurements) (SADABS; Blessing, 1995)	h = −10→10
Tmin = 0.649, Tmax = 0.838	k = −13→12
10019 measured reflections	l = −19→19

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)] = 0.039	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.109	H-atom parameters constrained
S = 1.06	w = 1/[σ^2(Fo^2) + (0.0666P)^2 + 0.4903P] where P = (Fo^2 + 2Fc^2)/3
5015 reflections	(Δ/σ)max = 0.001
307 parameters	Δρmax = 1.21 e Å^−3
0 restraints	Δρmin = −0.71 e Å^−3

Special details

Experimental. Mid-infrared (400-4000 cm^-1) spectra were collected using a Bio-Rad FTS-60 FTIR spectrometer operating at a resolution of 8 cm^-1. IR data for (I): ν(Cr-O) = 1442, 934, 784, cm^-1; ν(2,2'-bpy) = 3075, 3030, 763 cm^-1_.

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
Cu	0.03393 (4)	0.37189 (3)	0.739826 (19)	0.02157 (10)
Cr1	−0.39668 (5)	0.27925 (4)	0.76763 (3)	0.01993 (11)
Cr2	−0.25412 (6)	−0.03790 (4)	0.73794 (3)	0.02643 (12)
N1	−0.0723 (3)	0.4270 (2)	0.85717 (14)	0.0220 (4)
N2	0.1283 (3)	0.1927 (2)	0.83570 (14)	0.0210 (4)
N3	0.1163 (3)	0.3188 (2)	0.62001 (14)	0.0230 (4)
N4	0.1358 (3)	0.5488 (2)	0.66879 (14)	0.0217 (4)
O1	−0.4659 (3)	0.3287 (2)	0.86307 (15)	0.0372 (5)
O2	−0.2188 (2)	0.3457 (2)	0.71715 (12)	0.0258 (4)
O3	−0.5431 (3)	0.3272 (2)	0.69445 (15)	0.0403 (5)
O4	−0.3504 (3)	0.09246 (19)	0.80063 (13)	0.0294 (4)
O5	−0.3799 (3)	−0.1574 (2)	0.75802 (15)	0.0415 (5)
O6	−0.2244 (3)	0.0326 (2)	0.62719 (14)	0.0425 (5)
O7	−0.0658 (3)	−0.1068 (3)	0.77798 (16)	0.0477 (6)
C1	−0.1923 (3)	0.5424 (3)	0.86063 (19)	0.0259 (5)
H1	−0.2164	0.6090	0.8050	0.039*
C2	−0.2805 (3)	0.5648 (3)	0.9442 (2)	0.0287 (6)
H2	−0.3622	0.6454	0.9448	0.043*
C3	−0.2452 (3)	0.4653 (3)	1.02677 (19)	0.0281 (6)
H3	−0.3025	0.4787	1.0837	0.042*
C4	−0.1237 (3)	0.3454 (3)	1.02414 (18)	0.0252 (5)
H4	−0.0992	0.2772	1.0790	0.038*
C5	−0.0392 (3)	0.3290 (3)	0.93786 (17)	0.0208 (5)
C6	0.0874 (3)	0.2025 (3)	0.92594 (17)	0.0209 (5)
C7	0.1591 (4)	0.1005 (3)	1.00012 (18)	0.0275 (5)
H7	0.1307	0.1097	1.0614	0.041*
C8	0.2740 (3)	−0.0157 (3)	0.98151 (19)	0.0293 (6)
H8	0.3240	−0.0848	1.0301	0.044*
C9	0.3125 (3)	−0.0269 (3)	0.89005 (19)	0.0276 (5)
H9	0.3866	−0.1049	0.8762	0.041*
C10	0.2391 (3)	0.0798 (3)	0.81918 (18)	0.0250 (5)
H10	0.2678	0.0729	0.7575	0.037*
C11	0.0930 (3)	0.1991 (3)	0.60100 (19)	0.0282 (5)
H11	0.0382	0.1335	0.6475	0.042*
C12	0.1479 (4)	0.1695 (3)	0.5143 (2)	0.0311 (6)
H12	0.1306	0.0856	0.5028	0.047*
C13	0.2294 (4)	0.2683 (3)	0.44541 (19)	0.0331 (6)
H13	0.2692	0.2506	0.3870	0.050*
C14	0.2509 (4)	0.3933 (3)	0.46399 (18)	0.0290 (6)
H14	0.3031	0.4611	0.4179	0.043*
C15	0.1938 (3)	0.4163 (3)	0.55237 (17)	0.0228 (5)
C16	0.2105 (3)	0.5442 (3)	0.58097 (17)	0.0232 (5)
C17	0.2971 (3)	0.6519 (3)	0.52504 (19)	0.0301 (6)
H17	0.3437	0.6490	0.4643	0.045*
C18	0.3133 (4)	0.7642 (3)	0.5611 (2)	0.0336 (6)
H18	0.3720	0.8368	0.5248	0.050*
C19	0.2418 (4)	0.7672 (3)	0.6511 (2)	0.0349 (6)
H19	0.2530	0.8406	0.6768	0.052*
C20	0.1522 (4)	0.6575 (3)	0.70253 (19)	0.0290 (6)
H20	0.1018	0.6600	0.7628	0.044*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cu	0.02684 (18)	0.02115 (17)	0.01666 (16)	−0.00319 (12)	0.00047 (11)	−0.00616 (12)
Cr1	0.0198 (2)	0.0185 (2)	0.0202 (2)	−0.00031 (15)	−0.00126 (14)	−0.00448 (15)
Cr2	0.0345 (2)	0.0222 (2)	0.0213 (2)	−0.00266 (17)	0.00296 (17)	−0.00712 (17)
N1	0.0248 (10)	0.0217 (10)	0.0208 (10)	−0.0043 (8)	−0.0011 (8)	−0.0074 (8)
N2	0.0208 (10)	0.0204 (10)	0.0220 (10)	−0.0040 (8)	−0.0017 (8)	−0.0049 (8)
N3	0.0211 (10)	0.0284 (11)	0.0207 (10)	−0.0031 (8)	−0.0018 (8)	−0.0087 (9)
N4	0.0233 (10)	0.0206 (10)	0.0190 (10)	0.0007 (8)	−0.0027 (8)	−0.0032 (8)
O1	0.0487 (13)	0.0288 (10)	0.0328 (11)	−0.0057 (9)	0.0123 (9)	−0.0139 (9)
O2	0.0230 (9)	0.0303 (10)	0.0242 (9)	−0.0070 (7)	−0.0001 (7)	−0.0062 (7)
O3	0.0289 (10)	0.0440 (13)	0.0439 (12)	−0.0045 (9)	−0.0167 (9)	0.0023 (10)
O4	0.0419 (11)	0.0202 (9)	0.0259 (9)	−0.0017 (8)	−0.0023 (8)	−0.0080 (7)
O5	0.0561 (14)	0.0291 (11)	0.0417 (13)	−0.0141 (10)	0.0107 (10)	−0.0156 (10)
O6	0.0697 (16)	0.0363 (12)	0.0231 (10)	−0.0161 (11)	0.0002 (10)	−0.0072 (9)
O7	0.0408 (13)	0.0617 (16)	0.0390 (12)	0.0147 (11)	−0.0050 (10)	−0.0236 (11)
C1	0.0284 (13)	0.0231 (12)	0.0264 (13)	−0.0005 (10)	−0.0041 (10)	−0.0079 (10)
C2	0.0265 (13)	0.0263 (13)	0.0371 (15)	−0.0021 (10)	−0.0001 (10)	−0.0169 (11)
C3	0.0287 (13)	0.0311 (14)	0.0279 (13)	−0.0077 (11)	0.0041 (10)	−0.0147 (11)
C4	0.0279 (13)	0.0290 (13)	0.0211 (12)	−0.0086 (10)	0.0012 (9)	−0.0091 (10)
C5	0.0211 (11)	0.0225 (12)	0.0208 (11)	−0.0054 (9)	−0.0019 (9)	−0.0072 (9)
C6	0.0213 (11)	0.0217 (12)	0.0204 (11)	−0.0055 (9)	−0.0004 (9)	−0.0057 (9)
C7	0.0289 (13)	0.0310 (14)	0.0212 (12)	−0.0045 (11)	−0.0017 (10)	−0.0042 (10)
C8	0.0284 (13)	0.0259 (13)	0.0287 (14)	−0.0016 (11)	−0.0050 (10)	0.0012 (11)
C9	0.0254 (13)	0.0213 (12)	0.0326 (14)	−0.0013 (10)	0.0019 (10)	−0.0046 (10)
C10	0.0253 (12)	0.0252 (13)	0.0239 (12)	−0.0030 (10)	0.0018 (9)	−0.0079 (10)
C11	0.0262 (13)	0.0333 (14)	0.0282 (13)	−0.0062 (11)	−0.0014 (10)	−0.0121 (11)
C12	0.0285 (14)	0.0367 (15)	0.0329 (14)	0.0002 (11)	−0.0058 (11)	−0.0188 (12)
C13	0.0303 (14)	0.0459 (17)	0.0232 (13)	0.0070 (12)	−0.0067 (10)	−0.0150 (12)
C14	0.0275 (13)	0.0366 (15)	0.0180 (12)	0.0037 (11)	−0.0019 (9)	−0.0043 (10)
C15	0.0187 (11)	0.0288 (13)	0.0190 (11)	0.0018 (9)	−0.0050 (9)	−0.0046 (10)
C16	0.0218 (11)	0.0231 (12)	0.0205 (12)	0.0027 (9)	−0.0038 (9)	−0.0013 (9)
C17	0.0261 (13)	0.0307 (14)	0.0259 (13)	0.0002 (11)	−0.0002 (10)	0.0019 (11)
C18	0.0308 (14)	0.0244 (13)	0.0389 (16)	−0.0048 (11)	−0.0003 (12)	0.0026 (12)
C19	0.0384 (16)	0.0219 (13)	0.0431 (17)	−0.0049 (11)	−0.0002 (12)	−0.0073 (12)
C20	0.0352 (14)	0.0234 (13)	0.0272 (13)	−0.0029 (11)	0.0005 (10)	−0.0069 (10)

Geometric parameters (Å, º)

Cu—N3	1.977 (2)	C4—C5	1.392 (3)
Cu—N1	1.990 (2)	C4—H4	0.9300
Cu—N4	2.030 (2)	C5—C6	1.485 (3)
Cu—N2	2.054 (2)	C6—C7	1.390 (4)
Cu—O2	2.1161 (18)	C7—C8	1.391 (4)
Cr1—O3	1.609 (2)	C7—H7	0.9300
Cr1—O1	1.612 (2)	C8—C9	1.379 (4)
Cr1—O2	1.6429 (18)	C8—H8	0.9300
Cr1—O4	1.7720 (19)	C9—C10	1.386 (4)
Cr2—O6	1.610 (2)	C9—H9	0.9300
Cr2—O5	1.615 (2)	C10—H10	0.9300
Cr2—O7	1.626 (2)	C11—C12	1.388 (4)
Cr2—O4	1.7880 (18)	C11—H11	0.9300
N1—C1	1.349 (3)	C12—C13	1.388 (4)
N1—C5	1.353 (3)	C12—H12	0.9300
N2—C10	1.341 (3)	C13—C14	1.384 (4)
N2—C6	1.358 (3)	C13—H13	0.9300
N3—C11	1.340 (3)	C14—C15	1.390 (3)
N3—C15	1.356 (3)	C14—H14	0.9300
N4—C20	1.336 (3)	C15—C16	1.474 (4)
N4—C16	1.361 (3)	C16—C17	1.386 (4)
O4—Cr2	1.7880 (18)	C17—C18	1.390 (4)
C1—C2	1.384 (4)	C17—H17	0.9300
C1—H1	0.9300	C18—C19	1.380 (4)
C2—C3	1.382 (4)	C18—H18	0.9300
C2—H2	0.9300	C19—C20	1.394 (4)
C3—C4	1.387 (4)	C19—H19	0.9300
C3—H3	0.9300	C20—H20	0.9300
N3—Cu—N1	174.48 (8)	N1—C5—C4	121.6 (2)
N3—Cu—N4	81.16 (9)	N1—C5—C6	114.8 (2)
N1—Cu—N4	100.63 (8)	C4—C5—C6	123.6 (2)
N3—Cu—N2	101.57 (9)	N2—C6—C7	121.7 (2)
N1—Cu—N2	81.06 (8)	N2—C6—C5	114.7 (2)
N4—Cu—N2	133.32 (8)	C7—C6—C5	123.6 (2)
N3—Cu—O2	86.48 (8)	C6—C7—C8	119.1 (2)
N1—Cu—O2	88.12 (8)	C6—C7—H7	120.5
N4—Cu—O2	120.15 (8)	C8—C7—H7	120.5
N2—Cu—O2	106.51 (8)	C9—C8—C7	119.1 (2)
O3—Cr1—O1	111.36 (12)	C9—C8—H8	120.4
O3—Cr1—O2	108.68 (10)	C7—C8—H8	120.4
O1—Cr1—O2	110.93 (10)	C8—C9—C10	118.9 (2)
O3—Cr1—O4	109.53 (10)	C8—C9—H9	120.6
O1—Cr1—O4	106.18 (10)	C10—C9—H9	120.6
O2—Cr1—O4	110.14 (10)	N2—C10—C9	122.9 (2)
O6—Cr2—O5	110.62 (11)	N2—C10—H10	118.6
O6—Cr2—O7	109.43 (13)	C9—C10—H10	118.6
O5—Cr2—O7	110.13 (13)	N3—C11—C12	122.4 (3)
O6—Cr2—O4	110.88 (10)	N3—C11—H11	118.8
O5—Cr2—O4	108.99 (10)	C12—C11—H11	118.8
O7—Cr2—O4	106.71 (10)	C13—C12—C11	118.3 (3)
C1—N1—C5	119.0 (2)	C13—C12—H12	120.9
C1—N1—Cu	124.72 (18)	C11—C12—H12	120.9
C5—N1—Cu	115.52 (16)	C14—C13—C12	119.7 (3)
C10—N2—C6	118.3 (2)	C14—C13—H13	120.2
C10—N2—Cu	128.00 (17)	C12—C13—H13	120.2
C6—N2—Cu	113.12 (16)	C13—C14—C15	119.2 (3)
C11—N3—C15	119.5 (2)	C13—C14—H14	120.4
C11—N3—Cu	124.75 (18)	C15—C14—H14	120.4
C15—N3—Cu	115.70 (17)	N3—C15—C14	121.0 (2)
C20—N4—C16	118.8 (2)	N3—C15—C16	114.6 (2)
C20—N4—Cu	127.02 (17)	C14—C15—C16	124.4 (2)
C16—N4—Cu	113.77 (17)	N4—C16—C17	121.5 (2)
Cr1—O2—Cu	144.12 (11)	N4—C16—C15	114.6 (2)
Cr1—O4—Cr2	133.35 (11)	C17—C16—C15	123.9 (2)
N1—C1—C2	122.2 (2)	C16—C17—C18	119.0 (3)
N1—C1—H1	118.9	C16—C17—H17	120.5
C2—C1—H1	118.9	C18—C17—H17	120.5
C3—C2—C1	118.9 (2)	C19—C18—C17	119.6 (3)
C3—C2—H2	120.6	C19—C18—H18	120.2
C1—C2—H2	120.6	C17—C18—H18	120.2
C2—C3—C4	119.6 (2)	C18—C19—C20	118.4 (3)
C2—C3—H3	120.2	C18—C19—H19	120.8
C4—C3—H3	120.2	C20—C19—H19	120.8
C3—C4—C5	118.8 (2)	N4—C20—C19	122.7 (3)
C3—C4—H4	120.6	N4—C20—H20	118.7
C5—C4—H4	120.6	C19—C20—H20	118.7