The complex
trans-bis(hinokitiolato)copper(II) [systematic name:
trans-bis(3-isopropyl-7-oxocyclohepta-1,3,5-trienolato)copper(II); abbreviated name:
trans-Cu(hino)
2], [Cu(C
10H
11O
2)
2], is a biologically active compound. Three polymorphs of this square-planar monomer, all with (+
sp,−
sp) isopropyl substituents, have been reported previously. A fourth polymorph containing (+
ac,−
ac) isopropyl groups and its chloroform disolvate, [Cu(C
10H
11O
2)
2]·2CHCl
3, both exhibiting nonmerohedral twinning and with all Cu atoms on centers of crystallographic inversion symmetry, are reported here. One of the differences between all of these polymorphs is the relative conformation of the isopropyl groups with respect to the plane of the molecule. Stacking and Cu

olefin π distances ranging from 3.214 (4) to 3.311 (2) Å are observed, and the chloroform solvent molecules participate in bifurcated C—H

O hydrogen bonds [H

O = 2.26–2.40 Å, C

O = 3.123 (5)–3.214 (5) Å, C—H

O = 127–151° and O

H

O = 74°].
Supporting information
CCDC references: 755974; 755975
[cis-Cu(hino)2]2.[trans-Cu(hino)2]2.trans-
Cu(hino)2 was prepared by the literature procedure (Barret et al.,
2002). Room-temperature recrystallization from ethylene glycol–water
[Solvent ratio?] yielded green–yellow plates of (IV).
Recrystallization from chloroform yielded grey–green plates of (V). The
crystallographic quality of the latter degrades rapidly via solvent
loss. Retaining a small amount of mother liquor, a blanket of chloroform vapor
over the solids and/or speed in handling (V) are recommended.
The structures of (IV) and (V) were determined from nonmerohedrally twinned
data sets. The twin law for (IV) was [-1 0 0, -0.338 1 - 0.379, 0 0 - 1] and
corresponds to twinning by two-fold rotation about the a* axis. The
contributions from the major and minor components of the twinning were
0.741 (6) and 0.259 (6), respectively. The twin law for (V) was [-1 0 0, 0 - 1
0, 0.447 0.671 1] and corresponds to twinning by two-fold rotation about the
c* axis. The twinning was minor but still significant, with
contributions of 0.961 (2) and 0.039 (2) from the major and minor components,
respectively. The derivation of the twin laws and the subsequent generation of
HKLF 5 data sets for refinements were achieved using PLATON (Spek,
2009).
All H atoms were allowed to ride on their respective C atoms, with C—H
distances constrained to the SHELXTL (Sheldrick, 2008) default values
for the specified functional groups at 200 K, i.e. 0.95, 1.00 and 0.98 Å for the tropolone, methine and methyl H atoms, respectively. The
Uiso(H) values were set at 1.2Ueq(C) for the tropolone and
methine H atoms, and 1.5Ueq(C) for the methyl H atoms.
For both compounds, data collection: COLLECT (Nonius, 1998); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997); data reduction: DENZO-SMN (Otwinowski & Minor, 1997), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).
(IV) (+
ac,-
ac)-
trans-bis(3-isopropyl-7-oxocyclohepta-
1,3,5-trienolato)copper(II)
top
Crystal data top
[Cu(C10H11O2)2] | Z = 1 |
Mr = 389.92 | F(000) = 203 |
Triclinic, P1 | Dx = 1.468 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.3371 (2) Å | Cell parameters from 8954 reflections |
b = 8.4915 (5) Å | θ = 2.5–27.5° |
c = 8.7216 (5) Å | µ = 1.26 mm−1 |
α = 77.037 (2)° | T = 200 K |
β = 76.362 (3)° | Plate, green-yellow |
γ = 80.093 (3)° | 0.20 × 0.10 × 0.02 mm |
V = 440.93 (4) Å3 | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 2006 independent reflections |
Radiation source: fine-focus sealed tube | 1461 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.084 |
ω scans; 600 1.0° rotations | θmax = 27.5°, θmin = 2.5° |
Absorption correction: ψ scan (SHELXTL; Sheldrick, 2008) | h = −8→8 |
Tmin = 0.787, Tmax = 0.975 | k = −10→10 |
8954 measured reflections | l = −9→11 |
Refinement top
Refinement on F2 | Primary atom site location: isomorphous structure methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.065 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.204 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.1341P)2] where P = (Fo2 + 2Fc2)/3 |
2006 reflections | (Δ/σ)max < 0.001 |
118 parameters | Δρmax = 0.53 e Å−3 |
0 restraints | Δρmin = −0.83 e Å−3 |
Crystal data top
[Cu(C10H11O2)2] | γ = 80.093 (3)° |
Mr = 389.92 | V = 440.93 (4) Å3 |
Triclinic, P1 | Z = 1 |
a = 6.3371 (2) Å | Mo Kα radiation |
b = 8.4915 (5) Å | µ = 1.26 mm−1 |
c = 8.7216 (5) Å | T = 200 K |
α = 77.037 (2)° | 0.20 × 0.10 × 0.02 mm |
β = 76.362 (3)° | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 2006 independent reflections |
Absorption correction: ψ scan (SHELXTL; Sheldrick, 2008) | 1461 reflections with I > 2σ(I) |
Tmin = 0.787, Tmax = 0.975 | Rint = 0.084 |
8954 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.065 | 0 restraints |
wR(F2) = 0.204 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.53 e Å−3 |
2006 reflections | Δρmin = −0.83 e Å−3 |
118 parameters | |
Special details top
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 >
2σ(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 | Uiso*/Ueq | |
Cu1 | 1.0000 | 1.0000 | 0.0000 | 0.0392 (3) | |
O1 | 0.7824 (5) | 0.9796 (4) | 0.1949 (4) | 0.0373 (7) | |
O2 | 0.8394 (5) | 0.8586 (4) | −0.0569 (4) | 0.0402 (8) | |
C1 | 0.6366 (6) | 0.8883 (5) | 0.1962 (5) | 0.0321 (9) | |
C2 | 0.4724 (7) | 0.8603 (5) | 0.3351 (5) | 0.0337 (9) | |
H2 | 0.4867 | 0.9096 | 0.4191 | 0.040* | |
C3 | 0.2916 (7) | 0.7740 (5) | 0.3742 (5) | 0.0327 (9) | |
C4 | 0.2286 (7) | 0.6954 (5) | 0.2706 (5) | 0.0356 (10) | |
H4 | 0.0971 | 0.6472 | 0.3126 | 0.043* | |
C5 | 0.3307 (7) | 0.6778 (5) | 0.1152 (5) | 0.0364 (10) | |
H5 | 0.2577 | 0.6197 | 0.0665 | 0.044* | |
C6 | 0.5220 (7) | 0.7314 (5) | 0.0198 (5) | 0.0375 (10) | |
H6 | 0.5618 | 0.7018 | −0.0829 | 0.045* | |
C7 | 0.6662 (6) | 0.8227 (5) | 0.0510 (5) | 0.0331 (9) | |
C8 | 0.1586 (7) | 0.7671 (6) | 0.5446 (5) | 0.0372 (10) | |
H8 | 0.1701 | 0.8699 | 0.5782 | 0.045* | |
C9 | −0.0839 (7) | 0.7566 (6) | 0.5636 (6) | 0.0435 (11) | |
H9A | −0.1402 | 0.8338 | 0.4763 | 0.065* | |
H9B | −0.1638 | 0.7833 | 0.6672 | 0.065* | |
H9C | −0.1039 | 0.6458 | 0.5594 | 0.065* | |
C10 | 0.2610 (8) | 0.6252 (7) | 0.6584 (6) | 0.0545 (14) | |
H10A | 0.4092 | 0.6438 | 0.6590 | 0.082* | |
H10B | 0.2679 | 0.5232 | 0.6215 | 0.082* | |
H10C | 0.1714 | 0.6179 | 0.7674 | 0.082* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.0369 (5) | 0.0472 (6) | 0.0350 (5) | −0.0120 (3) | −0.0044 (3) | −0.0092 (4) |
O1 | 0.0378 (16) | 0.0438 (18) | 0.0337 (16) | −0.0140 (13) | −0.0066 (12) | −0.0089 (13) |
O2 | 0.0380 (17) | 0.051 (2) | 0.0307 (16) | −0.0134 (14) | 0.0028 (12) | −0.0112 (14) |
C1 | 0.034 (2) | 0.033 (2) | 0.032 (2) | −0.0034 (17) | −0.0104 (17) | −0.0071 (17) |
C2 | 0.036 (2) | 0.038 (2) | 0.031 (2) | −0.0041 (17) | −0.0077 (17) | −0.0133 (18) |
C3 | 0.033 (2) | 0.036 (2) | 0.029 (2) | −0.0035 (17) | −0.0052 (16) | −0.0086 (17) |
C4 | 0.033 (2) | 0.036 (2) | 0.038 (2) | −0.0074 (17) | −0.0054 (17) | −0.0060 (18) |
C5 | 0.039 (2) | 0.039 (2) | 0.034 (2) | −0.0090 (18) | −0.0069 (18) | −0.0108 (18) |
C6 | 0.040 (2) | 0.040 (3) | 0.032 (2) | −0.0051 (19) | −0.0048 (18) | −0.0092 (19) |
C7 | 0.034 (2) | 0.037 (2) | 0.028 (2) | −0.0023 (17) | −0.0082 (17) | −0.0046 (17) |
C8 | 0.043 (2) | 0.039 (3) | 0.032 (2) | −0.0071 (18) | −0.0072 (18) | −0.0088 (18) |
C9 | 0.038 (2) | 0.051 (3) | 0.038 (2) | −0.007 (2) | −0.0007 (19) | −0.009 (2) |
C10 | 0.045 (3) | 0.073 (4) | 0.037 (3) | −0.002 (2) | −0.008 (2) | 0.000 (2) |
Geometric parameters (Å, º) top
Cu1—O2i | 1.911 (3) | C5—C6 | 1.383 (6) |
Cu1—O2 | 1.911 (3) | C5—H5 | 0.9500 |
Cu1—O1 | 1.915 (3) | C6—C7 | 1.402 (6) |
Cu1—O1i | 1.915 (3) | C6—H6 | 0.9500 |
O1—C1 | 1.301 (5) | C8—C9 | 1.523 (6) |
O2—C7 | 1.297 (5) | C8—C10 | 1.535 (6) |
C1—C2 | 1.403 (6) | C8—H8 | 1.0000 |
C1—C7 | 1.455 (6) | C9—H9A | 0.9800 |
C2—C3 | 1.399 (6) | C9—H9B | 0.9800 |
C2—H2 | 0.9500 | C9—H9C | 0.9800 |
C3—C4 | 1.398 (6) | C10—H10A | 0.9800 |
C3—C8 | 1.521 (6) | C10—H10B | 0.9800 |
C4—C5 | 1.386 (6) | C10—H10C | 0.9800 |
C4—H4 | 0.9500 | | |
| | | |
O2i—Cu1—O2 | 180.000 (1) | C5—C6—H6 | 114.9 |
O2i—Cu1—O1 | 96.24 (12) | C7—C6—H6 | 114.9 |
O2—Cu1—O1 | 83.76 (12) | O2—C7—C6 | 119.7 (4) |
O2i—Cu1—O1i | 83.76 (12) | O2—C7—C1 | 114.9 (3) |
O2—Cu1—O1i | 96.24 (12) | C6—C7—C1 | 125.4 (4) |
O1—Cu1—O1i | 180.0 (2) | C3—C8—C9 | 114.8 (4) |
C1—O1—Cu1 | 112.9 (3) | C3—C8—C10 | 109.6 (4) |
C7—O2—Cu1 | 113.3 (3) | C9—C8—C10 | 110.4 (4) |
O1—C1—C2 | 118.1 (4) | C3—C8—H8 | 107.2 |
O1—C1—C7 | 115.1 (3) | C9—C8—H8 | 107.2 |
C2—C1—C7 | 126.8 (4) | C10—C8—H8 | 107.2 |
C3—C2—C1 | 132.6 (4) | C8—C9—H9A | 109.5 |
C3—C2—H2 | 113.7 | C8—C9—H9B | 109.5 |
C1—C2—H2 | 113.7 | H9A—C9—H9B | 109.5 |
C4—C3—C2 | 125.3 (4) | C8—C9—H9C | 109.5 |
C4—C3—C8 | 119.2 (4) | H9A—C9—H9C | 109.5 |
C2—C3—C8 | 115.5 (4) | H9B—C9—H9C | 109.5 |
C5—C4—C3 | 129.2 (4) | C8—C10—H10A | 109.5 |
C5—C4—H4 | 115.4 | C8—C10—H10B | 109.5 |
C3—C4—H4 | 115.4 | H10A—C10—H10B | 109.5 |
C6—C5—C4 | 130.2 (4) | C8—C10—H10C | 109.5 |
C6—C5—H5 | 114.9 | H10A—C10—H10C | 109.5 |
C4—C5—H5 | 114.9 | H10B—C10—H10C | 109.5 |
C5—C6—C7 | 130.1 (4) | | |
| | | |
O2i—Cu1—O1—C1 | 179.0 (3) | C4—C5—C6—C7 | −1.7 (8) |
O2—Cu1—O1—C1 | −1.0 (3) | Cu1—O2—C7—C6 | 174.5 (3) |
O1—Cu1—O2—C7 | 2.6 (3) | Cu1—O2—C7—C1 | −3.5 (5) |
O1i—Cu1—O2—C7 | −177.4 (3) | C5—C6—C7—O2 | 179.4 (4) |
Cu1—O1—C1—C2 | 178.1 (3) | C5—C6—C7—C1 | −2.8 (7) |
Cu1—O1—C1—C7 | −0.7 (4) | O1—C1—C7—O2 | 2.8 (6) |
O1—C1—C2—C3 | 178.0 (4) | C2—C1—C7—O2 | −175.8 (4) |
C7—C1—C2—C3 | −3.4 (8) | O1—C1—C7—C6 | −175.1 (4) |
C1—C2—C3—C4 | −2.5 (8) | C2—C1—C7—C6 | 6.3 (7) |
C1—C2—C3—C8 | 177.0 (4) | C4—C3—C8—C9 | −30.8 (6) |
C2—C3—C4—C5 | 3.5 (8) | C2—C3—C8—C9 | 149.7 (4) |
C8—C3—C4—C5 | −176.0 (4) | C4—C3—C8—C10 | 94.2 (5) |
C3—C4—C5—C6 | 0.4 (8) | C2—C3—C8—C10 | −85.4 (5) |
Symmetry code: (i) −x+2, −y+2, −z. |
(V) (+
ac,-
ac)-
trans-bis(3-isopropyl-7-oxocyclohepta-
1,3,5-trienolato)copper(II) chloroform disolvate
top
Crystal data top
[Cu(C10H11O2)2]·2CHCl3 | Z = 2 |
Mr = 628.65 | F(000) = 638 |
Triclinic, P1 | Dx = 1.584 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.1893 (2) Å | Cell parameters from 21329 reflections |
b = 8.4581 (3) Å | θ = 1.6–24.9° |
c = 25.7989 (10) Å | µ = 1.46 mm−1 |
α = 95.730 (2)° | T = 200 K |
β = 91.884 (2)° | Plate, grey-green |
γ = 100.878 (3)° | 0.23 × 0.13 × 0.03 mm |
V = 1317.82 (8) Å3 | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 4574 independent reflections |
Radiation source: fine-focus sealed tube | 3392 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.078 |
ω scans; 1200 0.5° rotations | θmax = 24.9°, θmin = 1.6° |
Absorption correction: ψ scan (SHELXTL; Sheldrick, 2008) | h = −7→7 |
Tmin = 0.734, Tmax = 0.964 | k = −10→9 |
21329 measured reflections | l = −5→30 |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.050 | H-atom parameters constrained |
wR(F2) = 0.136 | w = 1/[σ2(Fo2) + (0.0574P)2 + 1.8234P] where P = (Fo2 + 2Fc2)/3 |
S = 1.04 | (Δ/σ)max < 0.001 |
4574 reflections | Δρmax = 0.55 e Å−3 |
307 parameters | Δρmin = −0.62 e Å−3 |
0 restraints | Extinction correction: SHELXTL (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0050 (12) |
Crystal data top
[Cu(C10H11O2)2]·2CHCl3 | γ = 100.878 (3)° |
Mr = 628.65 | V = 1317.82 (8) Å3 |
Triclinic, P1 | Z = 2 |
a = 6.1893 (2) Å | Mo Kα radiation |
b = 8.4581 (3) Å | µ = 1.46 mm−1 |
c = 25.7989 (10) Å | T = 200 K |
α = 95.730 (2)° | 0.23 × 0.13 × 0.03 mm |
β = 91.884 (2)° | |
Data collection top
Nonius KappaCCD area-detector diffractometer | 4574 independent reflections |
Absorption correction: ψ scan (SHELXTL; Sheldrick, 2008) | 3392 reflections with I > 2σ(I) |
Tmin = 0.734, Tmax = 0.964 | Rint = 0.078 |
21329 measured reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.050 | 0 restraints |
wR(F2) = 0.136 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.55 e Å−3 |
4574 reflections | Δρmin = −0.62 e Å−3 |
307 parameters | |
Special details top
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 >
2σ(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 | Uiso*/Ueq | |
Cu1 | 0.5000 | 0.5000 | 1.0000 | 0.0366 (2) | |
O1 | 0.6415 (5) | 0.4882 (3) | 0.93554 (11) | 0.0380 (7) | |
O2 | 0.6893 (5) | 0.3606 (4) | 1.02021 (11) | 0.0402 (7) | |
C1 | 0.7920 (7) | 0.3990 (5) | 0.93523 (16) | 0.0324 (9) | |
C2 | 0.9035 (7) | 0.3768 (5) | 0.88963 (16) | 0.0354 (10) | |
H2 | 0.8585 | 0.4313 | 0.8619 | 0.042* | |
C3 | 1.0678 (7) | 0.2900 (5) | 0.87710 (17) | 0.0355 (10) | |
C4 | 1.1711 (7) | 0.2048 (5) | 0.91088 (18) | 0.0405 (10) | |
H4 | 1.2839 | 0.1543 | 0.8967 | 0.049* | |
C5 | 1.1301 (7) | 0.1845 (5) | 0.96221 (17) | 0.0394 (10) | |
H5 | 1.2236 | 0.1244 | 0.9783 | 0.047* | |
C6 | 0.9775 (7) | 0.2360 (5) | 0.99456 (17) | 0.0369 (10) | |
H6 | 0.9799 | 0.2041 | 1.0288 | 0.044* | |
C7 | 0.8200 (7) | 0.3285 (5) | 0.98366 (16) | 0.0344 (10) | |
C8 | 1.1288 (7) | 0.2866 (6) | 0.82041 (18) | 0.0439 (11) | |
H8 | 1.1269 | 0.3963 | 0.8094 | 0.053* | |
C9 | 1.3540 (8) | 0.2478 (7) | 0.8096 (2) | 0.0594 (14) | |
H9A | 1.4669 | 0.3229 | 0.8321 | 0.089* | |
H9B | 1.3841 | 0.2592 | 0.7729 | 0.089* | |
H9C | 1.3562 | 0.1365 | 0.8167 | 0.089* | |
C10 | 0.9511 (8) | 0.1653 (7) | 0.78681 (19) | 0.0605 (15) | |
H10A | 0.8084 | 0.1983 | 0.7906 | 0.091* | |
H10B | 0.9427 | 0.0573 | 0.7982 | 0.091* | |
H10C | 0.9884 | 0.1629 | 0.7502 | 0.091* | |
Cu2 | 0.5000 | 0.0000 | 0.5000 | 0.0359 (2) | |
O3 | 0.3278 (5) | −0.0286 (3) | 0.43581 (11) | 0.0366 (7) | |
O4 | 0.3209 (5) | 0.1517 (3) | 0.52118 (11) | 0.0386 (7) | |
C11 | 0.1800 (7) | 0.0614 (5) | 0.43630 (16) | 0.0322 (9) | |
C12 | 0.0447 (6) | 0.0544 (5) | 0.39081 (16) | 0.0330 (9) | |
H12 | 0.0738 | −0.0200 | 0.3630 | 0.040* | |
C13 | −0.1226 (7) | 0.1348 (5) | 0.37877 (16) | 0.0325 (9) | |
C14 | −0.2106 (7) | 0.2418 (5) | 0.41280 (17) | 0.0370 (10) | |
H14 | −0.3288 | 0.2839 | 0.3986 | 0.044* | |
C15 | −0.1475 (7) | 0.2947 (5) | 0.46472 (17) | 0.0372 (10) | |
H15 | −0.2339 | 0.3646 | 0.4813 | 0.045* | |
C16 | 0.0214 (7) | 0.2624 (5) | 0.49662 (16) | 0.0343 (9) | |
H16 | 0.0353 | 0.3160 | 0.5311 | 0.041* | |
C17 | 0.1731 (7) | 0.1626 (5) | 0.48525 (16) | 0.0326 (9) | |
C18 | −0.2114 (7) | 0.1031 (5) | 0.32202 (16) | 0.0386 (10) | |
H18 | −0.1984 | −0.0098 | 0.3089 | 0.046* | |
C19 | −0.4502 (8) | 0.1179 (6) | 0.31303 (19) | 0.0509 (12) | |
H19A | −0.5421 | 0.0530 | 0.3364 | 0.076* | |
H19B | −0.4994 | 0.0786 | 0.2767 | 0.076* | |
H19C | −0.4633 | 0.2316 | 0.3201 | 0.076* | |
C20 | −0.0622 (8) | 0.2197 (7) | 0.28999 (19) | 0.0553 (13) | |
H20A | −0.1045 | 0.1915 | 0.2528 | 0.083* | |
H20B | 0.0918 | 0.2106 | 0.2963 | 0.083* | |
H20C | −0.0791 | 0.3311 | 0.3005 | 0.083* | |
C21 | 0.4770 (8) | 0.7511 (6) | 0.87323 (19) | 0.0459 (11) | |
H21 | 0.4722 | 0.6606 | 0.8956 | 0.055* | |
Cl1 | 0.6028 (3) | 0.7017 (2) | 0.81496 (6) | 0.0792 (5) | |
Cl2 | 0.2062 (2) | 0.77513 (16) | 0.85920 (5) | 0.0561 (4) | |
Cl3 | 0.6298 (3) | 0.92920 (18) | 0.90753 (7) | 0.0751 (5) | |
C22 | 0.5322 (7) | 0.3384 (5) | 0.62680 (18) | 0.0401 (10) | |
H22 | 0.5147 | 0.2326 | 0.6045 | 0.048* | |
Cl4 | 0.7011 (2) | 0.33140 (18) | 0.68236 (5) | 0.0642 (4) | |
Cl5 | 0.6540 (2) | 0.49373 (15) | 0.59055 (5) | 0.0574 (4) | |
Cl6 | 0.2701 (2) | 0.36734 (16) | 0.64548 (5) | 0.0563 (4) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
Cu1 | 0.0396 (4) | 0.0388 (5) | 0.0347 (4) | 0.0139 (3) | 0.0049 (3) | 0.0075 (3) |
O1 | 0.0419 (17) | 0.0397 (17) | 0.0371 (17) | 0.0184 (14) | 0.0040 (13) | 0.0070 (13) |
O2 | 0.0443 (18) | 0.0466 (18) | 0.0342 (17) | 0.0166 (14) | 0.0077 (13) | 0.0100 (14) |
C1 | 0.034 (2) | 0.029 (2) | 0.034 (2) | 0.0066 (18) | 0.0018 (18) | 0.0038 (17) |
C2 | 0.034 (2) | 0.037 (2) | 0.035 (2) | 0.0077 (18) | −0.0004 (18) | 0.0055 (19) |
C3 | 0.032 (2) | 0.035 (2) | 0.038 (2) | 0.0037 (18) | 0.0010 (18) | 0.0014 (18) |
C4 | 0.040 (2) | 0.035 (2) | 0.048 (3) | 0.0107 (19) | 0.002 (2) | 0.002 (2) |
C5 | 0.040 (2) | 0.038 (3) | 0.043 (3) | 0.014 (2) | 0.001 (2) | 0.006 (2) |
C6 | 0.041 (2) | 0.036 (2) | 0.035 (2) | 0.0101 (19) | 0.0013 (19) | 0.0047 (19) |
C7 | 0.033 (2) | 0.032 (2) | 0.038 (2) | 0.0037 (18) | 0.0031 (18) | 0.0028 (18) |
C8 | 0.043 (3) | 0.047 (3) | 0.045 (3) | 0.014 (2) | 0.005 (2) | 0.006 (2) |
C9 | 0.040 (3) | 0.085 (4) | 0.054 (3) | 0.016 (3) | 0.013 (2) | 0.004 (3) |
C10 | 0.049 (3) | 0.094 (4) | 0.039 (3) | 0.024 (3) | 0.003 (2) | −0.009 (3) |
Cu2 | 0.0371 (4) | 0.0369 (4) | 0.0353 (4) | 0.0121 (3) | −0.0016 (3) | 0.0037 (3) |
O3 | 0.0364 (16) | 0.0379 (17) | 0.0385 (17) | 0.0146 (13) | 0.0010 (13) | 0.0053 (13) |
O4 | 0.0408 (17) | 0.0399 (17) | 0.0370 (17) | 0.0146 (13) | −0.0038 (13) | 0.0026 (13) |
C11 | 0.035 (2) | 0.026 (2) | 0.035 (2) | 0.0049 (18) | 0.0024 (18) | 0.0067 (17) |
C12 | 0.033 (2) | 0.031 (2) | 0.035 (2) | 0.0049 (17) | 0.0047 (17) | 0.0039 (18) |
C13 | 0.031 (2) | 0.030 (2) | 0.037 (2) | 0.0039 (17) | 0.0017 (17) | 0.0053 (18) |
C14 | 0.038 (2) | 0.033 (2) | 0.043 (3) | 0.0122 (19) | 0.0024 (19) | 0.0081 (19) |
C15 | 0.039 (2) | 0.030 (2) | 0.045 (3) | 0.0125 (18) | 0.0043 (19) | 0.0040 (19) |
C16 | 0.037 (2) | 0.035 (2) | 0.032 (2) | 0.0095 (18) | 0.0041 (18) | 0.0054 (18) |
C17 | 0.031 (2) | 0.029 (2) | 0.038 (2) | 0.0029 (17) | 0.0028 (18) | 0.0069 (18) |
C18 | 0.043 (3) | 0.041 (3) | 0.033 (2) | 0.014 (2) | −0.0054 (19) | 0.0017 (19) |
C19 | 0.043 (3) | 0.067 (3) | 0.043 (3) | 0.014 (2) | −0.006 (2) | 0.004 (2) |
C20 | 0.053 (3) | 0.076 (4) | 0.039 (3) | 0.014 (3) | 0.002 (2) | 0.013 (3) |
C21 | 0.051 (3) | 0.044 (3) | 0.047 (3) | 0.016 (2) | 0.000 (2) | 0.013 (2) |
Cl1 | 0.0895 (11) | 0.0970 (12) | 0.0644 (10) | 0.0391 (9) | 0.0246 (8) | 0.0255 (8) |
Cl2 | 0.0541 (8) | 0.0607 (8) | 0.0546 (8) | 0.0121 (6) | −0.0062 (6) | 0.0125 (6) |
Cl3 | 0.0709 (10) | 0.0596 (9) | 0.0882 (11) | −0.0025 (7) | −0.0239 (8) | 0.0141 (8) |
C22 | 0.042 (3) | 0.036 (2) | 0.043 (3) | 0.011 (2) | 0.006 (2) | 0.005 (2) |
Cl4 | 0.0601 (8) | 0.0795 (10) | 0.0547 (8) | 0.0179 (7) | −0.0052 (6) | 0.0098 (7) |
Cl5 | 0.0643 (8) | 0.0496 (7) | 0.0604 (8) | 0.0086 (6) | 0.0200 (6) | 0.0142 (6) |
Cl6 | 0.0477 (7) | 0.0561 (8) | 0.0673 (9) | 0.0133 (6) | 0.0135 (6) | 0.0081 (6) |
Geometric parameters (Å, º) top
Cu1—O2i | 1.907 (3) | O3—C11 | 1.296 (5) |
Cu1—O2 | 1.907 (3) | O4—C17 | 1.303 (5) |
Cu1—O1 | 1.908 (3) | C11—C12 | 1.409 (6) |
Cu1—O1i | 1.908 (3) | C11—C17 | 1.460 (6) |
O1—C1 | 1.304 (5) | C12—C13 | 1.385 (6) |
O2—C7 | 1.304 (5) | C12—H12 | 0.9500 |
C1—C2 | 1.398 (6) | C13—C14 | 1.394 (6) |
C1—C7 | 1.456 (6) | C13—C18 | 1.526 (6) |
C2—C3 | 1.390 (6) | C14—C15 | 1.388 (6) |
C2—H2 | 0.9500 | C14—H14 | 0.9500 |
C3—C4 | 1.397 (6) | C15—C16 | 1.393 (6) |
C3—C8 | 1.521 (6) | C15—H15 | 0.9500 |
C4—C5 | 1.378 (6) | C16—C17 | 1.395 (6) |
C4—H4 | 0.9500 | C16—H16 | 0.9500 |
C5—C6 | 1.383 (6) | C18—C19 | 1.519 (6) |
C5—H5 | 0.9500 | C18—C20 | 1.542 (7) |
C6—C7 | 1.398 (6) | C18—H18 | 1.0000 |
C6—H6 | 0.9500 | C19—H19A | 0.9800 |
C8—C9 | 1.519 (6) | C19—H19B | 0.9800 |
C8—C10 | 1.532 (7) | C19—H19C | 0.9800 |
C8—H8 | 1.0000 | C20—H20A | 0.9800 |
C9—H9A | 0.9800 | C20—H20B | 0.9800 |
C9—H9B | 0.9800 | C20—H20C | 0.9800 |
C9—H9C | 0.9800 | C21—Cl2 | 1.757 (5) |
C10—H10A | 0.9800 | C21—Cl3 | 1.757 (5) |
C10—H10B | 0.9800 | C21—Cl1 | 1.765 (5) |
C10—H10C | 0.9800 | C21—H21 | 1.0000 |
Cu2—O4ii | 1.900 (3) | C22—Cl5 | 1.757 (5) |
Cu2—O4 | 1.900 (3) | C22—Cl4 | 1.759 (5) |
Cu2—O3 | 1.909 (3) | C22—Cl6 | 1.761 (4) |
Cu2—O3ii | 1.909 (3) | C22—H22 | 1.0000 |
| | | |
O2i—Cu1—O2 | 180.00 (16) | C11—O3—Cu2 | 112.8 (2) |
O2i—Cu1—O1 | 95.56 (12) | C17—O4—Cu2 | 112.9 (3) |
O2—Cu1—O1 | 84.44 (12) | O3—C11—C12 | 118.5 (4) |
O2i—Cu1—O1i | 84.44 (12) | O3—C11—C17 | 115.1 (3) |
O2—Cu1—O1i | 95.56 (12) | C12—C11—C17 | 126.5 (4) |
O1—Cu1—O1i | 180.000 (2) | C13—C12—C11 | 132.4 (4) |
C1—O1—Cu1 | 113.0 (2) | C13—C12—H12 | 113.8 |
C7—O2—Cu1 | 112.3 (3) | C11—C12—H12 | 113.8 |
O1—C1—C2 | 118.6 (4) | C12—C13—C14 | 126.4 (4) |
O1—C1—C7 | 114.5 (4) | C12—C13—C18 | 115.0 (4) |
C2—C1—C7 | 126.9 (4) | C14—C13—C18 | 118.6 (4) |
C3—C2—C1 | 132.3 (4) | C15—C14—C13 | 128.3 (4) |
C3—C2—H2 | 113.9 | C15—C14—H14 | 115.8 |
C1—C2—H2 | 113.9 | C13—C14—H14 | 115.8 |
C2—C3—C4 | 126.0 (4) | C14—C15—C16 | 130.8 (4) |
C2—C3—C8 | 114.6 (4) | C14—C15—H15 | 114.6 |
C4—C3—C8 | 119.3 (4) | C16—C15—H15 | 114.6 |
C5—C4—C3 | 128.3 (4) | C15—C16—C17 | 129.3 (4) |
C5—C4—H4 | 115.9 | C15—C16—H16 | 115.4 |
C3—C4—H4 | 115.9 | C17—C16—H16 | 115.4 |
C4—C5—C6 | 131.6 (4) | O4—C17—C16 | 119.0 (4) |
C4—C5—H5 | 114.2 | O4—C17—C11 | 114.9 (4) |
C6—C5—H5 | 114.2 | C16—C17—C11 | 126.1 (4) |
C5—C6—C7 | 128.8 (4) | C19—C18—C13 | 115.3 (4) |
C5—C6—H6 | 115.6 | C19—C18—C20 | 109.9 (4) |
C7—C6—H6 | 115.6 | C13—C18—C20 | 108.3 (4) |
O2—C7—C6 | 118.2 (4) | C19—C18—H18 | 107.7 |
O2—C7—C1 | 115.8 (4) | C13—C18—H18 | 107.7 |
C6—C7—C1 | 126.0 (4) | C20—C18—H18 | 107.7 |
C9—C8—C3 | 115.6 (4) | C18—C19—H19A | 109.5 |
C9—C8—C10 | 109.6 (4) | C18—C19—H19B | 109.5 |
C3—C8—C10 | 108.9 (4) | H19A—C19—H19B | 109.5 |
C9—C8—H8 | 107.5 | C18—C19—H19C | 109.5 |
C3—C8—H8 | 107.5 | H19A—C19—H19C | 109.5 |
C10—C8—H8 | 107.5 | H19B—C19—H19C | 109.5 |
C8—C9—H9A | 109.5 | C18—C20—H20A | 109.5 |
C8—C9—H9B | 109.5 | C18—C20—H20B | 109.5 |
H9A—C9—H9B | 109.5 | H20A—C20—H20B | 109.5 |
C8—C9—H9C | 109.5 | C18—C20—H20C | 109.5 |
H9A—C9—H9C | 109.5 | H20A—C20—H20C | 109.5 |
H9B—C9—H9C | 109.5 | H20B—C20—H20C | 109.5 |
C8—C10—H10A | 109.5 | Cl2—C21—Cl3 | 110.1 (3) |
C8—C10—H10B | 109.5 | Cl2—C21—Cl1 | 110.1 (3) |
H10A—C10—H10B | 109.5 | Cl3—C21—Cl1 | 110.4 (3) |
C8—C10—H10C | 109.5 | Cl2—C21—H21 | 108.7 |
H10A—C10—H10C | 109.5 | Cl3—C21—H21 | 108.7 |
H10B—C10—H10C | 109.5 | Cl1—C21—H21 | 108.7 |
O4ii—Cu2—O4 | 180.00 (17) | Cl5—C22—Cl4 | 110.4 (3) |
O4ii—Cu2—O3 | 95.64 (12) | Cl5—C22—Cl6 | 110.6 (2) |
O4—Cu2—O3 | 84.36 (12) | Cl4—C22—Cl6 | 110.0 (2) |
O4ii—Cu2—O3ii | 84.36 (12) | Cl5—C22—H22 | 108.6 |
O4—Cu2—O3ii | 95.64 (12) | Cl4—C22—H22 | 108.6 |
O3—Cu2—O3ii | 180.000 (1) | Cl6—C22—H22 | 108.6 |
| | | |
O2i—Cu1—O1—C1 | 179.3 (3) | O4ii—Cu2—O3—C11 | 180.0 (3) |
O2—Cu1—O1—C1 | −0.7 (3) | O4—Cu2—O3—C11 | 0.0 (3) |
O1—Cu1—O2—C7 | 1.4 (3) | O3—Cu2—O4—C17 | 1.1 (3) |
O1i—Cu1—O2—C7 | −178.6 (3) | O3ii—Cu2—O4—C17 | −178.9 (3) |
Cu1—O1—C1—C2 | 178.2 (3) | Cu2—O3—C11—C12 | 178.7 (3) |
Cu1—O1—C1—C7 | −0.1 (4) | Cu2—O3—C11—C17 | −0.9 (4) |
O1—C1—C2—C3 | −179.6 (4) | O3—C11—C12—C13 | −179.0 (4) |
C7—C1—C2—C3 | −1.6 (8) | C17—C11—C12—C13 | 0.5 (7) |
C1—C2—C3—C4 | −3.0 (8) | C11—C12—C13—C14 | −4.7 (7) |
C1—C2—C3—C8 | 174.8 (4) | C11—C12—C13—C18 | 173.8 (4) |
C2—C3—C4—C5 | 1.9 (8) | C12—C13—C14—C15 | 2.2 (7) |
C8—C3—C4—C5 | −175.7 (4) | C18—C13—C14—C15 | −176.3 (4) |
C3—C4—C5—C6 | 1.9 (8) | C13—C14—C15—C16 | 2.5 (8) |
C4—C5—C6—C7 | −1.3 (8) | C14—C15—C16—C17 | −1.9 (8) |
Cu1—O2—C7—C6 | 175.9 (3) | Cu2—O4—C17—C16 | 176.2 (3) |
Cu1—O2—C7—C1 | −1.9 (4) | Cu2—O4—C17—C11 | −1.8 (4) |
C5—C6—C7—O2 | 178.8 (4) | C15—C16—C17—O4 | 179.1 (4) |
C5—C6—C7—C1 | −3.6 (7) | C15—C16—C17—C11 | −3.2 (7) |
O1—C1—C7—O2 | 1.4 (5) | O3—C11—C17—O4 | 1.9 (5) |
C2—C1—C7—O2 | −176.7 (4) | C12—C11—C17—O4 | −177.7 (4) |
O1—C1—C7—C6 | −176.3 (4) | O3—C11—C17—C16 | −176.0 (4) |
C2—C1—C7—C6 | 5.6 (7) | C12—C11—C17—C16 | 4.5 (7) |
C2—C3—C8—C9 | 159.0 (4) | C12—C13—C18—C19 | 151.7 (4) |
C4—C3—C8—C9 | −23.1 (6) | C14—C13—C18—C19 | −29.6 (6) |
C2—C3—C8—C10 | −77.1 (5) | C12—C13—C18—C20 | −84.7 (5) |
C4—C3—C8—C10 | 100.8 (5) | C14—C13—C18—C20 | 93.9 (5) |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, −y, −z+1. |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C21—H21···O1 | 1.00 | 2.26 | 3.167 (5) | 151 |
C21—H21···O2i | 1.00 | 2.43 | 3.138 (6) | 127 |
C22—H22···O3ii | 1.00 | 2.31 | 3.214 (5) | 149 |
C22—H22···O4 | 1.00 | 2.40 | 3.123 (5) | 129 |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, −y, −z+1. |
Experimental details
| (IV) | (V) |
Crystal data |
Chemical formula | [Cu(C10H11O2)2] | [Cu(C10H11O2)2]·2CHCl3 |
Mr | 389.92 | 628.65 |
Crystal system, space group | Triclinic, P1 | Triclinic, P1 |
Temperature (K) | 200 | 200 |
a, b, c (Å) | 6.3371 (2), 8.4915 (5), 8.7216 (5) | 6.1893 (2), 8.4581 (3), 25.7989 (10) |
α, β, γ (°) | 77.037 (2), 76.362 (3), 80.093 (3) | 95.730 (2), 91.884 (2), 100.878 (3) |
V (Å3) | 440.93 (4) | 1317.82 (8) |
Z | 1 | 2 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 1.26 | 1.46 |
Crystal size (mm) | 0.20 × 0.10 × 0.02 | 0.23 × 0.13 × 0.03 |
|
Data collection |
Diffractometer | Nonius KappaCCD area-detector diffractometer | Nonius KappaCCD area-detector diffractometer |
Absorption correction | ψ scan (SHELXTL; Sheldrick, 2008) | ψ scan (SHELXTL; Sheldrick, 2008) |
Tmin, Tmax | 0.787, 0.975 | 0.734, 0.964 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8954, 2006, 1461 | 21329, 4574, 3392 |
Rint | 0.084 | 0.078 |
(sin θ/λ)max (Å−1) | 0.649 | 0.593 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.065, 0.204, 1.03 | 0.050, 0.136, 1.04 |
No. of reflections | 2006 | 4574 |
No. of parameters | 118 | 307 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.53, −0.83 | 0.55, −0.62 |
Hydrogen-bond geometry (Å, º) for (V) top
D—H···A | D—H | H···A | D···A | D—H···A |
C21—H21···O1 | 1.00 | 2.26 | 3.167 (5) | 151 |
C21—H21···O2i | 1.00 | 2.43 | 3.138 (6) | 127 |
C22—H22···O3ii | 1.00 | 2.31 | 3.214 (5) | 149 |
C22—H22···O4 | 1.00 | 2.40 | 3.123 (5) | 129 |
Symmetry codes: (i) −x+1, −y+1, −z+2; (ii) −x+1, −y, −z+1. |
Comparative geometric parameters (Å, °) for monomeric
trans-Cu(C10H11O2)2 polymorphs top | (I)a | (II)b | (II)c |
Cu1-O1 | 1.900 (2) | 1.920 (2) | 1.915 (2) |
Cu1-O2 | 1.904 (3) | 1.906 (2) | 1.901 (2) |
O1-C1 | 1.296 (5) | 1.297 (4) | 1.295 (3) |
O2-C7 | 1.293 (5) | 1.302 (4) | 1.289 (4) |
O1-Cu1-O2 | 83.84 (13) | 84.06 (9) | 83.70 (9) |
Cu1-O1-C1 | 113.5 (3) | 112.9 (2) | 113.0 (2) |
Cu1-O2-C7 | 113.5 (3) | 113.4 (2) | 113.5 (2) |
C2-C3-C8 | 116.5 (4) | 116.5 (3) | 116.8 (3) |
C4-C3-C8 | 117.4 (4) | 116.8 (3) | 117.4 (3) |
C2-C3-C8-Xe | -4.6 (6) | 12.4 (4) | -13.4 (4) |
| | | |
| (III)c | (IV)d | (V)d |
Cu1-O1 | 1.918 (2) | 1.915 (3) | 1.908 (3) |
Cu1-O2 | 1.913 (2) | 1.911 (3) | 1.904 (3) |
O1-C1 | 1.292 (3) | 1.301 (5) | 1.300 (5) |
O2-C7 | 1.293 (3) | 1.297 (5) | 1.304 (5) |
O1-Cu1-O2 | 83.90 (8) | 83.76 (12) | 84.40 (12) |
Cu1-O1-C1 | 112.9 (2) | 112.9 (3) | 112.9 (2) |
Cu1-O2-C7 | 112.7 (2) | 113.3 (3) | 112.6 (3) |
C2-C3-C8 | 116.5 (2) | 115.5 (4) | 114.8 (4) |
C4-C3-C8 | 117.5 (3) | 119.2 (4) | 119.0 (4) |
C2-C3-C8-Xe | 0.9 (3) | -147.8 (6) | -142.8 (6) |
(a) Barret et al. (2002);
(b) Nomiya, Yoshizawa, Kasuga et al. (2004), corrected;
(c) Arvanitis et al. (2004);
(d) this work, where the values for (V) are averages over two
independent molecules;
(e) torsion angles for all samples are averages over X = C9 and C10. |
Hinokitiol (β-thujaplicin), a natural product first isolated from Chamaecyparis taiwanensis (Nozoe, 1936), is a tropolone possessing antimicrobial activity. Its antibacterial and antifungal properties have contributed to its widespread utilization in agricultural and personal care products. Not surprisingly, it is also an excellent ligand for the chelation of metal ions. Hence metal hinokitiolate complexes, M(hino)x, have also come under renewed interest and scrutiny. For example, Cu, Zn and Sn hinokitiolate complexes have been examined for their suitability in oral care products (Creeth et al., 2000), one polymorph of trans-Cu(hino)2 has been shown to possess antibacterial properties (Nomiya, Yoshizawa, Tsukagoshi et al., 2004; Nomiya, Yoshizawa, Kasuga et al., 2004), and Cu(hino)2 has been reported to inhibit the replication of human influenza viruses (Miyamoto et al., 1998). In the last example, our use of Cu(hino)2 without qualifications is to specify that, to our knowledge, the identity of the compound in that study is not known with certainty.
Antibacterial studies involving Cu indicate a growing need for more precise language and nomenclature in the discussion of these compounds. Readers are cautioned that Cu(hino)2 as written does not imply a single compound. Rather, Cu(hino)2 is shorthand for a family of compounds. The members of that family include cis-Cu(hino)2, trans-Cu(hino)2, and any combination of monomers, dimers and/or oligomers with the empirical formulation Cu(hino)2. Molloy and co-workers were the first to `report on the unusual structural chemistry' of Cu(hino)2 (Barret et al., 2002). The cis monomer has yet to be isolated in pure form, the trans monomer is polymorphic, and a third family member, i.e. [cis-Cu(hino)2]2.[trans-Cu(hino)2]2.trans- Cu(hino)2, has been confirmed. The last was used as the starting material for this study.
It is also important to clarify that the 1:1:1 combination of cis-dimer:trans-dimer:trans-monomer has never been shown to pack in any arrangement other than that reported in 2002, and hence cannot be said to be polymorphic. Further, it is not a polymorph of the cis- or trans-monomeric members of the family. To transform one family member into another requires geometric isomerization and/or covalent bond breaking and bond making, and as such they are not polymorphs of each other by the most widely accepted definition of polymorphism (McCrone, 1965). These polymers (dimers, oligomers, etc.) and dynamic isomers (as stated by McCrone) `cannot be called polymorphs although they may behave in a confusingly similar manner'. Currently, only one member within the Cu(hino)2 family of compounds, i.e. trans-Cu(hino)2, has been established with certainty to be polymorphic.
Three polymorphs of trans-Cu(hino)2 have been previously described in the literature, and we report here on a fourth polymorph and its chloroform disolvate. Polymorphs (I) (Barret et al., 2002), (II) (Nomiya, Yoshizawa, Kasuga et al., 2004; Arvanitis et al., 2004) and (III) (Arvanitis et al., 2004) contain (+sp,-sp)-trans-Cu(hino)2, while the new polymorph, (IV), and its chloroform disolvate, (V), contain (+ac,-ac)-trans-Cu(hino)2. The synperiplanar (sp) and anticlinal (ac) designators specify the average methyl orientation of each isopropyl group relative to the tropolone ring to which it is attached (see Fig. 1). The + and - signs with the sp designators are not standard nomenclature (Moss, 1996); they are used here to clarify that sp substituents can indeed possess positive and negative values, and to help specify whether the average methyl vectors are rotated slightly to one side or to opposite sides of the best plane through the molecule. Also, our convention is that a syn isopropyl substituent will have its average methyl vector oriented inwards or towards the half of the tropolone molecule containing the metal atom, and conversely, an anti isopropyl group will have its methyl vector directed outwards or away from the metal. Views of (IV) and (V) are given in Fig. 2, and comparative geometric parameters for (I)–(V) are summarized in Table 1.
Triclinic green–yellow plates of (IV) and grey–green plates of (V) were obtained by recrystallization of [cis-Cu(hino)2]2.[trans-Cu(hino)2]2.trans- Cu(hino)2 from ethylene glycol–water and chloroform, respectively. The Cu atoms in all forms of monomeric trans-Cu(hino)2, i.e. (I)–(V), reside on centers of crystallographic inversion symmetry and have square-planar coordination geometries. The five atoms of the CuO4 cores in these monomers are required by symmetry to be coplanar. All core bond distances and angles in (I)–(V), with the possible exception of (II), are statistically equivalent (see Table 1). Subtle structural variations do of course exist as one moves outwards away from the CuO4 core. In (I) and (II), the Cu(tropolone)2 moieties, i.e. excluding the isopropyl substituents, are best described as planar. In (III), a 7.1 (1)° folding along the O1···O2 vector is observed. In (IV) and (V), each half-moiety exhibits a 4.5 (2)° torsional twist (see Fig. 3). Clearly, any computational study regarding polymorph prediction for trans-Cu(hino)2 would need to consider the conformational flexibility of the Cu(tropolone)2 moiety, in addition to the rotational degrees of freedom of the isopropyl substituents and intermolecular packing interactions.
As shown in Table 1, the geometry at atom C3 is the most meaningful, and it should come as no surprise that the positioning and orientation of the isopropyl substituents should vary from one polymorph to another. In (I)–(III), the C2—C3—C8 angles are slightly smaller than the C4—C3—C8 angles, but all are near 117°. In (IV) and (V), C2—C3—C8 and C4—C3—C8 are significantly different, with the latter approaching 120°. The C2—C3—C8—X torsion angles in (I)–(III) are also noticably different than those in (IV) and (V). These are the hallmarks for (+sp,-sp) isopropyl substituents in (I)–(III) and for (+ac,-ac) isopropyl substituents in (IV) and (V). These angular and torsional differences are also observed in hinokitiol itself (Derry & Hamor, 1972; Ohishi et al., 1994; Tanaka et al., 2001), and are generally applicable to other metal hinokitiolate complexes as well (Nomiya et al., 2009). Exceptions will inevitably occur with changes in coordination geometries.
The crystal structures of (II)–(V) are consistent with the presence of weak Cu—olefin π interactions. With the exception of (I), the trans-Cu(hino)2 molecules in these polymorphs pack into extended columns or stacks, such that the π-systems of neighboring molecules are positioned above and below each formally four-coordinate Cu atom. Segments of that stacking for (IV) and (V) are shown in Fig. 3. The Cu atom is 3.336 (1) Å from the centroid defined by atoms C1/C4–C7 in (II), and 3.226 (2), 3.290 (4) and 3.290 (4) Å from the centroid of the C4—C5 bond in (III)–(V), respectively. For (IV) and (V), the closest contacts are actually shifted towards atom C5 and are 3.258 (4) and 3.214 (4) Å, respectively. These distances may be compared with values of 3.25–3.55 Å reported for longer-range noncovalent Cu···arene contacts (Mascal et al., 2000). The distances between the least-squares planes through adjacent molecules, or stacking distances, are 3.336 (1), 3.235 (2), 3.311 (2) and 3.257 (2) Å for (II)–(V), respectively. The Cu···Cu distances between neighboring molecules within a stack are 5.1549 (3), 6.7470 (1), 6.3371 (2) and 6.1893 (2) Å for (II)–(V), respectively, and correspond to a unit translation in the crystallographic a direction for (II), (IV) and (V), and in the b direction for (III). The slippages (see Fig. 3) of one molecule from orthogonal coincidence with a neighboring molecule within a stack are 3.930 (1), 5.921 (2), 5.403 (2) and 5.263 (2) Å for (II)–(V), respectively. It is remarkable that, in spite of the presence of solvent molecules in (V), its trans-Cu(hino)2 stacks are strikingly similar to those in (IV). The only visual difference in the segments shown in Fig. 3 would appear to be the orientations of the isopropyl groups. Clearly, the reader is encouraged to examine the data above and not just illustrations when comparing such closely related structures.
Finally, each trans-monomer in (V) is also hydrogen-bonded to two chloroform molecules, and so, not surprisingly, the chloroform molecules are also organized into columns running parallel to the crystallographic a axis. The bifurcated hydrogen bonding is shown in Fig. 2. The distances and angles are C21—H21 = 1.00 Å, H21···O1 = 2.26 Å, H21···O2ii = 2.43 Å, C21···O1 = 3.167 (5) Å, C21···O2ii = 3.138 (6) Å, C21—H21···O1 = 151°, C21—H21···O2ii = 127° and O1···H21···O2ii = 74° for one of the crystallographically independent chloroform molecules in the asymmetric unit, and C22—H22 = 1.00 Å, H22···O3iii = 2.31 Å, H22···O4 = 2.40 Å, C22···O3iii = 3.214 (5) Å, C22···O4 = 3.123 (5) Å, C22—H22···O3iii = 149°, C22—H22···O4 = 129° and O3iii···H22···O4 = 74° for the other [symmetry codes: (ii) 1 - x, 1 - y, 2 - z, (iii) 1 - x, -y, 1 - z]. We are not aware of any published examples of bifurcated chloroform hydrogen bonds with metal tropolone complexes. However, there is a plethora of bifurcated chloroform hydrogen bonds with other complexes, among which are two examples containing square-planar CuO4 cores (Maverick et al., 1986; Pariya et al., 2007). The distances and angles in those examples are C—H = 1.00 Å, H···O = 2.32–2.42 Å, C···O = 3.101–3.281 Å, C—H···O = 132–146° and O···H···O = 66–67°, similar enough to say that the hydrogen bonding in (V) is normal.
In summary, (+ac,-ac)-trans-Cu(hino)2, (IV), and its chloroform disolvate, (V), have been crystallographically characterized. The hinokitiolate O atoms in (V) participate in hydrogen bonding. Hydrogen bonding was also previously observed in (III) (Arvanitis et al., 2004). These observations are at odds with the suggestion that the formation of the CuO4 core inhibits an interaction of the O atoms with microorganisms/proteins (Nomiya , Yoshizawa, Tsukagoshi et al., 2004). If C—H···O(hino) hydrogen bonding is possible, surely the stronger N—H···O(hino) and O—H···O(hino) interactions are possible as well.