2-(Biphenyl-4-yl)propan-2-ol

Eric Modau; David C Liles; Petrus H van Rooyen

doi:10.1107/S1600536812003716

. 2012 Feb 4;68(Pt 3):o580. doi: 10.1107/S1600536812003716

2-(Biphenyl-4-yl)propan-2-ol

Eric Modau ^a, David C Liles ^a, Petrus H van Rooyen ^a,^*

PMCID: PMC3297307 PMID: 22412497

Abstract

The title compound, C₁₅H₁₆O, crystallizes with two independent molecules in the asymmetric unit. Due to the space-group symmetry, this results in the formation of a tetramer where the four molecules are connected by O—H⋯O hydrogen bonds. The molecules pack parallel to the c axis. Both molecules in the asymmetric unit are nonplanar and the dihedral angles between connected aromatic rings in each molecule are 7.96 (12) and 9.75 (13)°. This contrasts with the gas phase density functional theory (DFT) optimized conformation, where this dihedral angle is 39.33°.

Related literature

For some previous studies of biphenyl derivitives, see: Britton & Gleason (1991 ▶); Britton & Young (2003 ▶); Brock (1980 ▶); Brock & Haller (1980 ▶); Mohamed et al. (2003 ▶). For details of GAUSSIAN03, see: Frisch et al. (2003 ▶).

Experimental

Crystal data

C₁₅H₁₆O
M _r = 212.28
Monoclinic,
a = 12.4406 (14) Å
b = 15.5754 (18) Å
c = 25.741 (3) Å
β = 102.332 (2)°
V = 4872.7 (10) Å³
Z = 16
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 295 K
0.46 × 0.36 × 0.08 mm

Data collection

Bruker P4 diffractometer with SMART 1000 CCD area detector
Absorption correction: multi-scan (SADABS; Bruker, 2001 ▶) T _min = 0.931, T _max = 0.994
12927 measured reflections
4590 independent reflections
2859 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.147
S = 1.01
4590 reflections
391 parameters
3 restraints
All H-atom parameters refined
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.14 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL and SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶), Mercury (Macrae et al., 2008 ▶) and POV-RAY (Cason, 2004 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812003716/zq2152sup1.cif

e-68-0o580-sup1.cif^{(31.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812003716/zq2152Isup2.hkl

e-68-0o580-Isup2.hkl^{(225KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812003716/zq2152Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1A⋯O2	0.90 (1)	1.99 (2)	2.804 (2)	150 (4)
O2—H2A⋯O1	0.90 (1)	2.09 (4)	2.804 (2)	136 (4)
O1—H1B⋯O1ⁱ	0.87 (3)	1.90 (3)	2.767 (3)	174 (4)
O2—H2B⋯O2ⁱ	0.89 (1)	2.03 (1)	2.926 (3)	177 (4)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors thank the University of Pretoria for financial support.

supplementary crystallographic information

Comment

The studies of the series of biphenyl derivatives have attracted considerable attention for some time now. This included the para-monosubstituted derivatives 4-bromobiphenyl (Brock, 1980) and 4-hydroxylbiphenyl (Brock & Haller, 1980), as well as some para-disubstituted derivatives such as 4,4'-dibromobiphenyl (Mohamed et al., 2003), 4,4'-iodocyanobiphenyl (Britton & Gleason, 1991) and 4,4'-dicyanobiphenyl (Britton & Young, 2003). Particular interest has been shown in their packing motifs as well as the inter-ring dihedral angles which are found to be approximately 40° in the solid state in the majority of structures. The structure of the corresponding 2-(4-biphenyl)-2-propanol compound, was undertaken as part of the investigation into the conformational properties of para monosubstituted and para disubstituted biphenyls. Of significance is that this compound crystallizes in a significantly more planar conformation than what is expected, although it is still non-planar.

2-(4-biphenyl)-2-propanol crystallizes with two independent molecules in the asymmetric unit. The presence of a twofold rotational axis results in the formation of a hydrogen bonded tetramer. The four H atoms of the hydroxyl groups occupy both sets of possible hydrogen positions, illustrated by the two possible bonding schemes (H···O_A—H···O_B—H) and (H—O_A···H—O_B···H). Both sets of H atom positions were refined with occupancies of 0.5. The two molecules in the asymmetric unit have similar geometrical parameters. The molecules are non-planar: the two aromatic rings in each molecule are slightly twisted around C—C inter ring bond by 7.96 (3)° and 9.75 (3)°. This contrasts to the gas phase DFT (6–31+G**) optimized conformation where this dihedral angle is 39.33° (GAUSSIAN03, Frisch et al., 2003). The anisotropic displacement ellipsoids and atom labelling for the compound is shown in Fig.1. The lengths of the central C—C bonds connecting the two aromatic rings in each of the two molecules are equal to 1.491 (3) and 1.489 (2) Å. The bond length and bond angle are within the expected values. The H···O distances are 1.99 (2), 2.09 (4), 1.90 (3) and 2.034 (11) Å. The molecules pack parallel to the c axis (Fig. 2). The volume per non H atom in the crystal is 19.03 Å³, in line with that calculated for other biphenyl derivatives structures. This would suggest that the closer packing resulting from the intermolecular hydrogen bonds as well as the more planar biphenyl systems does not significantly change the packing requirements in the crystals.

Experimental

The title compound was obtained from Aldrich Chemical Co. Inc. Crystals were grown from distilled hexane, acetone, benzene, dichloromethane, chloroform, carbon tetrachloride, and acetonitrile in an attempt to search for multiple polymorphs. Several habits were found, viz. prisms, clear plates, and striated plates but all proved to be isostructural. A prism grown from distilled hexane was used for the structure determination.

Geometry optimization for 2-(4-biphenyl)-2-propanol was performed using the program GAUSSIAN03 and applying the B3LYP-functional with the 6-31+G** basis set level (Frisch et al., 2003). This optimized structure displayed no negative vibrational frequencies.