CIF access Acta Cryst. (1999). C55, IUC9900067 [ doi:10.1107/s0108270199099163 ] Redetermination of biphenylene at 130K R. Boese, D. Bläser and R. Latz Abstract Biphenylene is one of the key compounds in the discussion of bond localization in aromatic systems, usually addressed as Mills-Nixon-Effect (Mills & Nixon, 1930; Maksic et al., 1999). A pronounced bond localization due to the Mills-Nixon-Effect in the direction of one of the Kekule forms is established. Compared to the previous structure determination by Fawcett and Trotter (1966) the significance of bond length alternation in respect to the s.u.'s in the six membered rings has been dramatically increased. Comment Biphenylene is one of the key compounds in the discussion of bond localization in aromatic systems, usually addressed as Mills-Nixon-Effect (Mills & Nixon, 1930; Maksic et al., 1999). A pronounced bond localization due to the Mills-Nixon-Effect in the direction of one of the Kekule forms is established. Compared to the previous structure determination by Fawcett and Trotter (1966) the significance of bond length alternation in respect to the s.u.'s in the six membered rings has been dramatically increased. Scheme of the framework of Biphenylene: /\ c / \ / \ / \ / \ / a -b d \ / -f e \ / \ / \ / \ / \/ \/ Bond length mean values: a b 1.5175 (13) Å, b c 1.3750 (12) Å, c d 1.4248 (10) Å, d e 1.3917 (10) Å, b f 1.4283 (12) Å. Experimental Commercial Product Computing details Data collection: P3-VMS (Siemens, 1987); cell refinement: P3-VMS (Siemens, 1987); data reduction: XDISK (Siemens, 1987); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXL97 (Sheldrick, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 1997). Biphenylene
CIF access Crystal data C 12 H 8 V = 1191.8 (5) Å 3 M r = 152.18 Z = 6 Monoclinic, P2 1 /c Mo Kα a = 5.8094 (13) Å µ = 0.07 mm 1 b = 10.466 (3) Å T = 130 (2) K c = 19.605 (5) Å 0.31 0.23 0.17 mm β = 90.998 (19)º Data collection Nicolet R3m/V four-circle diffractometer Absorption correction: none R int = 0.062 1 standard reflections 5142 measured reflections every 100 reflections 3468 independent reflections intensity decay: <3% 2854 reflections with I > 2σ(I) Refinement R[F 2 > 2σ(F 2 )] = 0.052 212 parameters wr(f 2 ) = 0.149 All H-atom parameters refined S = 1.03 Δρ max = 0.51 e Å 3 3468 reflections Δρ min = 0.28 e Å 3 Acknowledgements We thank the Fonds der Chemischen Industrie for financial support. References Mills, W. H. & Nixon, I. G. (1930). J. Chem. Soc. pp. 2510. Maksic, Z. B., et al. (1999). Theoretical and Computational Chemistry, edited by P. Politzer & Z. B. Maksic, Paulings Legacy - Modern Modelling of the Chemical Bond, Vol. 6, edited by Z. B. Maksic & W. J. Orville-Thomas, The Mills-Nixon Effect: Fallacies, Facts and Chemical Relevance Amsterdam: Elsevier. Fawcett, J. K. & Trotter, J. (1966). Acta Cryst. 20, 87 93. Sheldrick, G. M. (1990). Acta Cryst. A46, 467 473. Sheldrick, G. M. (1997). SHELXL97. Program for the Refinement of Crystal Structures. University of Göttingen, Germany. Siemens (1987). P3-VMS Diffractometer Program. Version 4.1. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA. Siemens (1991). XDISK. Data Reduction Program. Version 4.20.2PC. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.
Scheme 1 CIF access
Biphenylene Crystal data C 12 H 8 F 000 = 480 M r = 152.18 Monoclinic, P2 1 /c a = 5.8094 (13) Å D x = 1.272 Mg m 3 Mo Kα radiation λ = 0.71073 Å b = 10.466 (3) Å θ = 10.0 12.5º c = 19.605 (5) Å β = 90.998 (19)º V = 1191.8 (5) Å 3 Z = 6 Cell parameters from 50 reflections µ = 0.07 mm 1 T = 130 (2) K Block, colourless 0.31 0.23 0.17 mm Data collection Nicolet R3m/V four-circle diffractometer R int = 0.062 Radiation source: fine-focus sealed tube θ max = 30º Monochromator: graphite θ min = 2.1º T = 130(2) K Wyckoff scan mode Absorption correction: none h = 8 8 k = 11 14 l = 0 27 5142 measured reflections 1 standard reflections 3468 independent reflections every 100 reflections 2854 reflections with I > 2σ(I) intensity decay: <3% Refinement Refinement on F 2 Least-squares matrix: full R[F 2 > 2σ(F 2 )] = 0.052 Hydrogen site location: difference Fourier map All H-atom parameters refined w = 1/[σ 2 (F o 2 ) + (0.099P) 2 + 0.2829P] where P = (F o 2 + 2F c 2 )/3 wr(f 2 ) = 0.149 (Δ/σ) max = 0.001 S = 1.03 Δρ max = 0.51 e Å 3 3468 reflections Δρ min = 0.28 e Å 3 212 parameters Primary atom site location: structure-invariant direct methods Secondary atom site location: difference Fourier map Extinction correction: SHELXL97, Fc * =kfc[1+0.001xfc 2 λ 3 /sin(2θ)] -1/4 Extinction coefficient: 0.007 (4) sup-1
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 F 2 against ALL reflections. The weighted R-factor wr and goodness of fit S are based on F 2, conventional R-factors R are based on F, with F set to zero for negative F 2. The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 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 (Å 2 ) x y z U iso */U eq C1 0.64965 (19) 0.99538 (10) 0.47149 (5) 0.0169 (2) C2 0.8288 (2) 1.00814 (11) 0.42679 (6) 0.0187 (2) H2 0.959 (3) 0.9551 (17) 0.4270 (9) 0.028 (4)* C3 0.8043 (2) 1.10745 (11) 0.37753 (6) 0.0201 (2) H3 0.930 (3) 1.1180 (16) 0.3423 (8) 0.024 (4)* C4 0.6115 (2) 1.18630 (11) 0.37484 (6) 0.0207 (2) H4 0.604 (3) 1.2532 (18) 0.3385 (8) 0.027 (4)* C5 0.4260 (2) 1.17155 (11) 0.42077 (6) 0.0194 (2) H5 0.290 (3) 1.2258 (16) 0.4176 (8) 0.021 (4)* C6 0.45075 (19) 1.07571 (11) 0.46839 (5) 0.0169 (2) C7 0.77246 (19) 0.51055 (10) 0.30637 (5) 0.0161 (2) C8 0.5917 (2) 0.50144 (11) 0.26045 (6) 0.0190 (2) H8 0.450 (3) 0.5537 (16) 0.2631 (8) 0.024 (4)* C9 0.6195 (2) 0.40920 (12) 0.20782 (6) 0.0212 (2) H9 0.497 (3) 0.3984 (17) 0.1743 (9) 0.030 (4)* C10 0.8157 (2) 0.33338 (12) 0.20339 (6) 0.0210 (2) H10 0.824 (3) 0.2720 (17) 0.1650 (8) 0.023 (4)* C11 1.0034 (2) 0.34503 (11) 0.25094 (6) 0.0191 (2) H11 1.144 (3) 0.2918 (16) 0.2461 (8) 0.025 (4)* C12 0.97587 (19) 0.43478 (11) 0.30138 (5) 0.0165 (2) C13 1.07480 (19) 0.50005 (10) 0.36438 (6) 0.0168 (2) C14 1.2586 (2) 0.51383 (11) 0.40879 (6) 0.0191 (2) H14 1.399 (3) 0.4648 (18) 0.4052 (9) 0.029 (4)* C15 1.2304 (2) 0.60613 (12) 0.46125 (6) 0.0213 (2) H15 1.355 (3) 0.6235 (17) 0.4952 (9) 0.026 (4)* C16 1.0301 (2) 0.67799 (12) 0.46690 (6) 0.0214 (3) H16 1.017 (3) 0.7400 (18) 0.5034 (9) 0.026 (4)* C17 0.8410 (2) 0.66393 (11) 0.42022 (6) 0.0193 (2) H17 0.702 (3) 0.7188 (17) 0.4247 (8) 0.025 (4)* C18 0.87017 (19) 0.57459 (10) 0.36988 (5) 0.0165 (2) sup-2
Atomic displacement parameters (Å 2 ) U 11 U 22 U 33 U 12 U 13 U 23 C1 0.0204 (5) 0.0151 (5) 0.0151 (5) 0.0012 (4) 0.0019 (4) 0.0001 (4) C2 0.0194 (5) 0.0193 (5) 0.0174 (5) 0.0005 (4) 0.0009 (4) 0.0012 (4) C3 0.0240 (5) 0.0205 (5) 0.0159 (5) 0.0048 (4) 0.0013 (4) 0.0006 (4) C4 0.0276 (6) 0.0169 (5) 0.0176 (5) 0.0041 (4) 0.0012 (4) 0.0016 (4) C5 0.0231 (5) 0.0163 (5) 0.0189 (5) 0.0010 (4) 0.0012 (4) 0.0010 (4) C6 0.0191 (5) 0.0162 (5) 0.0154 (5) 0.0008 (4) 0.0002 (4) 0.0008 (4) C7 0.0182 (5) 0.0148 (5) 0.0152 (5) 0.0006 (4) 0.0015 (4) 0.0000 (3) C8 0.0190 (5) 0.0215 (5) 0.0165 (5) 0.0022 (4) 0.0011 (4) 0.0013 (4) C9 0.0232 (5) 0.0244 (6) 0.0160 (5) 0.0012 (4) 0.0022 (4) 0.0009 (4) C10 0.0248 (6) 0.0214 (5) 0.0170 (5) 0.0021 (4) 0.0019 (4) 0.0039 (4) C11 0.0200 (5) 0.0177 (5) 0.0196 (5) 0.0007 (4) 0.0023 (4) 0.0018 (4) C12 0.0170 (5) 0.0160 (5) 0.0164 (5) 0.0009 (4) 0.0009 (4) 0.0010 (4) C13 0.0186 (5) 0.0151 (5) 0.0167 (5) 0.0007 (4) 0.0013 (4) 0.0002 (4) C14 0.0186 (5) 0.0193 (5) 0.0193 (5) 0.0009 (4) 0.0011 (4) 0.0016 (4) C15 0.0244 (5) 0.0230 (5) 0.0163 (5) 0.0057 (4) 0.0032 (4) 0.0009 (4) C16 0.0278 (6) 0.0201 (5) 0.0163 (5) 0.0056 (4) 0.0021 (4) 0.0024 (4) C17 0.0214 (5) 0.0181 (5) 0.0186 (5) 0.0004 (4) 0.0037 (4) 0.0017 (4) C18 0.0172 (5) 0.0163 (5) 0.0161 (5) 0.0016 (4) 0.0008 (4) 0.0008 (4) Geometric parameters (Å, ) C1 C2 1.3786 (16) C9 C10 1.3924 (17) C1 C6 1.4294 (15) C9 H9 0.966 (18) C1 C6 i 1.5189 (15) C10 C11 1.4277 (17) C2 C3 1.4242 (16) C10 H10 0.991 (16) C2 H2 0.937 (18) C11 C12 1.3753 (16) C3 C4 1.3913 (17) C11 H11 0.994 (16) C3 H3 1.019 (16) C12 C13 1.5157 (16) C4 C5 1.4248 (17) C13 C14 1.3735 (16) C4 H4 0.999 (17) C13 C18 1.4275 (15) C5 C6 1.3762 (15) C14 C15 1.4225 (17) C5 H5 0.972 (16) C14 H14 0.966 (18) C6 C1 i 1.5189 (15) C15 C16 1.3918 (18) C7 C8 1.3747 (15) C15 H15 0.990 (17) C7 C12 1.4279 (15) C16 C17 1.4249 (17) C7 C18 1.5156 (15) C16 H16 0.970 (18) C8 C9 1.4244 (16) C17 C18 1.3722 (15) C8 H8 0.988 (17) C17 H17 0.994 (17) C2 C1 C6 122.32 (10) C9 C10 C11 121.83 (11) C2 C1 C6 i 147.68 (11) C9 C10 H10 117.9 (9) C6 C1 C6 i 90.00 (9) C11 C10 H10 120.2 (9) C1 C2 C3 115.73 (11) C12 C11 C10 115.51 (10) C1 C2 H2 123.8 (11) C12 C11 H11 123.9 (9) C3 C2 H2 120.5 (11) C10 C11 H11 120.6 (9) sup-3
C4 C3 C2 121.97 (11) C11 C12 C7 122.38 (10) C4 C3 H3 119.7 (9) C11 C12 C13 147.83 (11) C2 C3 H3 118.3 (9) C7 C12 C13 89.79 (9) C3 C4 C5 121.94 (10) C14 C13 C18 122.27 (10) C3 C4 H4 117.8 (10) C14 C13 C12 147.50 (11) C5 C4 H4 120.2 (10) C18 C13 C12 90.20 (9) C6 C5 C4 115.88 (10) C13 C14 C15 115.57 (11) C6 C5 H5 123.0 (9) C13 C14 H14 123.0 (11) C4 C5 H5 121.2 (9) C15 C14 H14 121.4 (11) C5 C6 C1 122.17 (10) C16 C15 C14 122.10 (11) C5 C6 C1 i 147.84 (11) C16 C15 H15 116.6 (10) C1 C6 C1 i 90.00 (9) C14 C15 H15 121.3 (10) C8 C7 C12 122.71 (10) C15 C16 C17 121.96 (11) C8 C7 C18 147.10 (11) C15 C16 H16 119.6 (10) C12 C7 C18 90.19 (9) C17 C16 H16 118.4 (10) C7 C8 C9 115.23 (10) C18 C17 C16 115.40 (11) C7 C8 H8 123.5 (10) C18 C17 H17 124.6 (10) C9 C8 H8 121.2 (10) C16 C17 H17 120.0 (10) C10 C9 C8 122.33 (11) C17 C18 C13 122.70 (10) C10 C9 H9 119.0 (11) C17 C18 C7 147.46 (11) C8 C9 H9 118.7 (11) C13 C18 C7 89.81 (9) Symmetry codes: (i) x+1, y+2, z+1. sup-4