Ethane-1,2-diylbis(methyl-phosphinic acid).

In the title compound, C(4)H(12)O(4)P(2), there are two crystallographically independent half-mol-ecules in the asymmetric unit, both molecules lying on centres of symmetry. Each mol-ecule is connected on both sides to neighbouring mol-ecules via strong O-H⋯O hydrogen bonds. The -POOH groups accept and donate one hydrogen bond in interactions with the neighbouring -POOH group of the adjacent mol-ecule, to give one-dimensional chains along [10]. As each phosphinic acid group donates and accepts one hydrogen bond, the connection between the mol-ecules is best described by a ring motif which can be classified by the Etter symbol R(2) (2)(8).

Related literature

For related literature, see: Bruckmann et al. (1999 ▶); Etter et al. (1990 ▶); Sicken et al. (2000 ▶).

Experimental

Crystal data

C4H12O4P2

M = 186.08

Monoclinic,

a = 6.7761 (18) Å

b = 18.703 (8) Å

c = 6.8401 (15) Å

β = 102.09 (3)°

V = 847.7 (5) Å3

Z = 4

Mo Kα radiation

μ = 0.47 mm−1

T = 290 (2) K

0.40 × 0.35 × 0.30 mm

Data collection

Nicolet/Siemens P21/P3 four-circle diffractometer

Absorption correction: none

4847 measured reflections

2466 independent reflections

1879 reflections with I > 2σ(I)

R int = 0.023

3 standard reflections every 100 reflections intensity decay: none

Refinement

R[F 2 > 2σ(F 2)] = 0.035

wR(F 2) = 0.079

S = 1.01

2466 reflections

139 parameters

All H-atom parameters refined

Δρmax = 0.35 e Å−3

Δρmin = −0.34 e Å−3

Data collection: R3m/V Software (Siemens, 1989 ▶); cell refinement: R3m/V Software; data reduction: R3m/V Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: DIAMOND (Brandenburg, 2001 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807068122/pk2077sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807068122/pk2077Isup2.hkl

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

C4H12O4P2	F000 = 392
Mr = 186.08	Dx = 1.458 Mg m−3
Monoclinic, P21/c	Mo Kα radiation λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 37 reflections
a = 6.7761 (18) Å	θ = 5.1–14.3º
b = 18.703 (8) Å	µ = 0.47 mm−1
c = 6.8401 (15) Å	T = 290 (2) K
β = 102.09 (3)º	Block, colourless
V = 847.7 (5) Å3	0.40 × 0.35 × 0.30 mm
Z = 4

Nicolet/Siemens P21/P3-four-circle diffractometer	Rint = 0.023
Radiation source: fine-focus sealed tube	θmax = 30.0º
Monochromator: graphite	θmin = 2.2º
T = 290(2) K	h = 0→9
ω scans	k = −26→26
Absorption correction: none	l = −9→9
4847 measured reflections	3 standard reflections
2466 independent reflections	every 100 reflections
1879 reflections with I > 2σ(I)	intensity decay: none

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.035	All H-atom parameters refined
wR(F2) = 0.079	w = 1/[σ2(Fo2) + (0.025P)2 + 0.41P] where P = (Fo2 + 2Fc2)/3
S = 1.01	(Δ/σ)max = 0.003
2466 reflections	Δρmax = 0.35 e Å−3
139 parameters	Δρmin = −0.34 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

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 > 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.

	x	y	z	Uiso*/Ueq
P1	0.10537 (7)	0.60187 (2)	0.89929 (7)	0.03542 (12)
O1	0.0298 (2)	0.59213 (9)	0.6716 (2)	0.0477 (3)
H1	0.114 (6)	0.606 (2)	0.586 (6)	0.145 (15)*
O2	0.32968 (19)	0.59006 (8)	0.96702 (19)	0.0455 (3)
C1	0.0385 (5)	0.68801 (12)	0.9733 (4)	0.0563 (6)
H11	0.067 (4)	0.6933 (14)	1.116 (4)	0.070 (8)*
H12	0.106 (5)	0.7222 (17)	0.917 (5)	0.094 (10)*
H13	−0.088 (4)	0.6940 (15)	0.925 (4)	0.075 (9)*
C2	−0.0220 (3)	0.53869 (9)	1.0246 (3)	0.0371 (4)
H21	0.017 (3)	0.5445 (12)	1.163 (3)	0.047 (6)*
H22	−0.157 (3)	0.5475 (12)	0.984 (3)	0.051 (6)*
P2	0.48253 (7)	0.61724 (2)	0.51341 (7)	0.03302 (11)
O3	0.25753 (19)	0.62778 (7)	0.44442 (18)	0.0412 (3)
O4	0.5560 (2)	0.62903 (7)	0.7409 (2)	0.0421 (3)
H4	0.470 (5)	0.6132 (18)	0.826 (5)	0.117 (12)*
C3	0.6086 (4)	0.67852 (12)	0.3826 (4)	0.0501 (5)
H31	0.575 (4)	0.7228 (16)	0.410 (4)	0.078 (8)*
H32	0.565 (4)	0.6729 (14)	0.247 (4)	0.065 (8)*
H33	0.738 (4)	0.6751 (15)	0.426 (4)	0.079 (9)*
C4	0.5508 (3)	0.52908 (9)	0.4481 (3)	0.0343 (3)
H41	0.693 (3)	0.5257 (11)	0.494 (3)	0.042 (5)*
H42	0.513 (3)	0.5270 (11)	0.311 (3)	0.044 (6)*

	U11	U22	U33	U12	U13	U23
P1	0.0352 (2)	0.0375 (2)	0.0329 (2)	−0.00097 (17)	0.00569 (17)	0.00385 (18)
O1	0.0359 (7)	0.0712 (10)	0.0338 (7)	−0.0062 (6)	0.0024 (5)	0.0038 (6)
O2	0.0350 (7)	0.0632 (9)	0.0364 (7)	−0.0004 (6)	0.0030 (5)	0.0047 (6)
C1	0.0677 (16)	0.0365 (10)	0.0624 (16)	0.0033 (10)	0.0087 (12)	0.0018 (10)
C2	0.0403 (9)	0.0362 (9)	0.0361 (9)	0.0017 (7)	0.0108 (7)	0.0015 (7)
P2	0.0359 (2)	0.02862 (19)	0.0346 (2)	−0.00337 (16)	0.00759 (17)	0.00217 (17)
O3	0.0379 (7)	0.0472 (7)	0.0371 (7)	0.0038 (5)	0.0047 (5)	0.0049 (5)
O4	0.0374 (7)	0.0493 (8)	0.0378 (7)	−0.0064 (6)	0.0037 (5)	−0.0068 (6)
C3	0.0576 (14)	0.0369 (10)	0.0563 (13)	−0.0105 (9)	0.0133 (11)	0.0095 (9)
C4	0.0380 (9)	0.0299 (8)	0.0357 (9)	−0.0019 (7)	0.0095 (7)	0.0018 (7)

P1—O2	1.5096 (14)	P2—O3	1.5115 (14)
P1—O1	1.5452 (15)	P2—O4	1.5468 (14)
P1—C1	1.776 (2)	P2—C3	1.779 (2)
P1—C2	1.7850 (19)	P2—C4	1.7942 (19)
O1—H1	0.94 (4)	O4—H4	0.95 (4)
C1—H11	0.96 (3)	C3—H31	0.89 (3)
C1—H12	0.92 (3)	C3—H32	0.92 (3)
C1—H13	0.86 (3)	C3—H33	0.87 (3)
C2—C2i	1.529 (3)	C4—C4ii	1.539 (3)
C2—H21	0.93 (2)	C4—H41	0.95 (2)
C2—H22	0.91 (2)	C4—H42	0.92 (2)
O2—P1—O1	113.08 (8)	O3—P2—O4	112.74 (8)
O2—P1—C1	110.24 (12)	O3—P2—C3	108.55 (11)
O1—P1—C1	110.11 (12)	O4—P2—C3	109.08 (11)
O2—P1—C2	108.23 (9)	O3—P2—C4	109.76 (8)
O1—P1—C2	108.33 (9)	O4—P2—C4	109.63 (8)
C1—P1—C2	106.60 (11)	C3—P2—C4	106.90 (11)
P1—O1—H1	119 (2)	P2—O4—H4	118 (2)
P1—C1—H11	112.0 (16)	P2—C3—H31	108.9 (18)
P1—C1—H12	109.5 (19)	P2—C3—H32	110.5 (16)
H11—C1—H12	110 (2)	H31—C3—H32	106 (2)
P1—C1—H13	107.7 (19)	P2—C3—H33	109.7 (19)
H11—C1—H13	110 (2)	H31—C3—H33	106 (3)
H12—C1—H13	107 (3)	H32—C3—H33	115 (2)
C2i—C2—P1	112.62 (17)	C4ii—C4—P2	111.78 (16)
C2i—C2—H21	107.8 (14)	C4ii—C4—H41	108.8 (12)
P1—C2—H21	110.3 (13)	P2—C4—H41	106.0 (12)
C2i—C2—H22	109.4 (15)	C4ii—C4—H42	112.7 (13)
P1—C2—H22	106.6 (14)	P2—C4—H42	105.1 (13)
H21—C2—H22	110.1 (18)	H41—C4—H42	112.3 (17)
O2—P1—C2—C2i	−61.3 (2)	O3—P2—C4—C4ii	−62.1 (2)
O1—P1—C2—C2i	61.7 (2)	O4—P2—C4—C4ii	62.3 (2)
C1—P1—C2—C2i	−179.8 (2)	C3—P2—C4—C4ii	−179.64 (19)

D—H···A	D—H	H···A	D···A	D—H···A
O4—H4···O2	0.95 (4)	1.55 (4)	2.504 (2)	178 (3)
O1—H1···O3	0.94 (4)	1.56 (4)	2.499 (2)	179 (4)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O4—H4⋯O2	0.95 (4)	1.55 (4)	2.504 (2)	178 (3)
O1—H1⋯O3	0.94 (4)	1.56 (4)	2.499 (2)	179 (4)