Chemical bonding in pentaerythritol at very low temperature or at high pressure: an experimental and theoretical study

Chemical bonding in the pentaerythritol crystal based on the experimental electron density at 15 (1) K, and theoretical calculations at the experimental molecular geometries obtained at room and low (15 K) temperatures have been analyzed and compared in terms of the topological analysis. Topological electron-density features corresponding to the high-pressure (1.15 GPa) geometry are also reported. In addition to the bond critical points (CPs) within the molecular layers, CPs between the atoms of different molecular layers have been located and the bonding character of these relatively weak interactions discussed. Atomic charges and energies have been integrated over the atomic basins delimited by the zero-flux surfaces, and the intermolecular interaction energies have been calculated. The interaction between molecular layers in the crystal becomes stronger both at very low temperature and high pressure, as demonstrated by the more negative intermolecular interaction energies, higher electron density and energy density values at the CPs, and sharper electronic-energy density profiles.

S1. Experimental

? _publ_section_exptl_refinement

Computing details

Data collection: CrystalClear,(2005); cell refinement: Otwinowski & Minor (1997); data reduction: Zhurov et al.,(2005); program(s) used to solve structure: Sheldrick (1997); program(s) used to refine structure: Koritsanszky et al., (2003); molecular graphics: Koritsanszky et al., (2003); software used to prepare material for publication: Koritsanszky et al., (2003).

Figures

(PE)

Crystal data

C5H12O4	Mo Kα radiation, λ = 0.71073 Å
Mr = 135.15	Cell parameters from 29440 reflections
Tetragonal, I4	θ = 0–70°
a = 6.0867 (1) Å	µ = 0.12 mm^−1
c = 8.4958 (4) Å	T = 15 K
V = 314.75 Å^3	Tetragonal bipyramid, colorless
Z = 2	0.30 × 0.30 × 0.25 mm
Dx = 1.434 Mg m^−3

Data collection

Rigaku R-axis Rapid diffractometer	Rint = 0.018
w scans	θmax = 70.1°
29440 measured reflections	h = 0→16
29440 independent reflections	k = 0→16
27057 reflections with I > 4σ	l = −22→22

Refinement

Refinement on F^2	All H-atom parameters refined
R[F^2 > 2σ(F^2)] = 0.012	w = 1/[s^2(Fsqd)]
wR(F^2) = 0.012	(Δ/σ)max < 0.001
S = 1.51	Δρmax = 0.06 e Å^−3
2378 reflections	Δρmin = −0.06 e Å^−3
125 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
O(1)	−0.31978 (2)	−0.24540 (2)	0.01876 (2)	0.008
C(1)	0.00000	0.00000	0.00000	0.005
C(2)	−0.16021 (2)	−0.12529 (2)	0.10680 (1)	0.007
H(1)	−0.06946	−0.23630	0.18188	0.024 (2)
H(2)	−0.24692	−0.01404	0.18196	0.025 (2)
H(3)	−0.26608	−0.38641	−0.00055	0.021 (2)
DUM0	1.00000	0.00000	0.00000	0.000	0.0000
DUM1	0.00000	1.00000	0.00000	0.000	0.0000
DUM2	0.14270	0.01660	−0.10640	0.000	0.0000
DUM3	−0.01800	0.14110	−0.10740	0.000	0.0000

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O(1)	0.00565 (3)	0.00622 (3)	0.01263 (4)	−0.00103 (2)	−0.00037 (3)	−0.00075 (3)
C(1)	0.00455 (3)	0.00455 (3)	0.00549 (6)	0.00000	0.00000	0.00000
C(2)	0.00639 (3)	0.00626 (3)	0.00688 (3)	−0.00093 (2)	0.00079 (3)	0.00032 (3)

Geometric parameters (Å, º)

O(1)—C(2)	1.4273 (2)	C(1)—C(2)^ii	1.5348 (1)
O(1)—H(3)	0.9330 (1)	C(1)—C(2)^iii	1.5348 (1)
C(1)—C(2)	1.5348 (1)	C(2)—H(1)	1.0810 (1)
C(1)—C(2)^i	1.5348 (1)	C(2)—H(2)	1.0700 (1)
C(2)—O(1)—H(3)	108.960 (13)	O(1)—C(2)—H(1)	109.681 (11)
C(2)—C(1)—C(2)^i	107.522 (9)	O(1)—C(2)—H(2)	107.530 (10)
C(2)—C(1)—C(2)^ii	110.454 (5)	C(1)—C(2)—H(1)	109.560 (8)
C(2)—C(1)—C(2)^iii	110.454 (5)	C(1)—C(2)—H(2)	110.596 (8)
C(2)^i—C(1)—C(2)^ii	110.454 (5)	C(1)^i—C(2)—H(1)	109.560 (8)
C(2)^i—C(1)—C(2)^iii	110.454 (5)	C(1)^i—C(2)—H(2)	110.596 (8)
C(2)^ii—C(1)—C(2)^iii	107.522 (9)	C(1)^ii—C(2)—H(1)	109.560 (8)
O(1)—C(2)—C(1)	112.152 (10)	C(1)^ii—C(2)—H(2)	110.596 (8)
O(1)—C(2)—C(1)^i	112.152 (10)	C(1)^iii—C(2)—H(1)	109.560 (8)
O(1)—C(2)—C(1)^ii	112.152 (10)	C(1)^iii—C(2)—H(2)	110.596 (8)
O(1)—C(2)—C(1)^iii	112.152 (10)	H(1)—C(2)—H(2)	107.180 (11)

Symmetry codes: (i) −x, −y, z; (ii) y, −x, −z; (iii) −y, x, −z.