Diiso­propyl­ammonium chloride hemihydrate, a combined single-crystal and powder diffraction study

By the reaction of diiso­propyl­amine (dip) with hydro­chloric acid and crystallization at room temperature, dipHCl, known from the literature, and the corresponding hemihydrate, C₆H₁₆N⁺·Cl^-·0.5H₂O or dipHCl·0.5H₂O, have been obtained. By using a new humidity chamber for the powder diffraction study it has been proven that dipHCl reacts via a solid-solid phase transition to give dipHCl·0.5H₂O on increasing the relative humidity of the sample atmosphere. The cations and anions are connected by hydrogen bonds to form chains along the crystallographic [100] direction. The extended polymeric zigzag chains form layers in the ac plane, separated by water mol­ecules. The cations and water molecules lie on crystallographic twofold rotation axes.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.004 Å
• Disorder in solvent or counterion
• R factor = 0.043
• wR factor = 0.100
• Data-to-parameter ratio = 15.2

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level B:



RINTA_01  Alert B The value of Rint is greater than 0.15
          Rint given   0.168


 Alert Level C:



PLAT_302  Alert C Anion/Solvent Disorder .......................       6.00 Perc.


 0 Alert Level A = Potentially serious problem

 1 Alert Level B = Potential problem

 1 Alert Level C = Please check

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Computing details

Data collection: IPDS Software (Stoe & Cie, 1998); cell refinement: IPDS Software; data reduction: IPDS Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997).

(I)

Crystal data

C6H16N^+·Cl^−·0.5H2O	Dx = 1.039 Mg m^−3
Mr = 146.66	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Ccca	Cell parameters from 5000 reflections
a = 10.289 (2) Å	θ = 2.6–25.7°
b = 15.723 (3) Å	µ = 0.34 mm^−1
c = 11.590 (2) Å	T = 293 K
V = 1874.9 (6) Å^3	Platelet, colourless
Z = 8	0.35 × 0.1 × 0.01 mm
F(000) = 648

Data collection

Stoe IPDS diffractometer	574 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.168
Graphite monochromator	θmax = 25.0°, θmin = 4.2°
Detector resolution: 50 pixels mm^-1	h = −12→12
ω scans	k = −18→18
11427 measured reflections	l = −13→13
819 independent reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.043	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.100	w = 1/[σ^2(Fo^2) + (0.01P)^2 + 1.09P] where P = (Fo^2 + 2Fc^2)/3
S = 1.09	(Δ/σ)max < 0.001
819 reflections	Δρmax = 0.31 e Å^−3
54 parameters	Δρmin = −0.26 e Å^−3
1 restraint	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0035 (10)

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 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 > σ(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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
N1	0.2500	0.0000	0.6094 (2)	0.0421 (6)
H1	0.1819 (15)	0.0161 (14)	0.6529 (17)	0.052 (6)*
C1	0.1991 (2)	−0.07534 (14)	0.5419 (2)	0.0505 (6)
H1A	0.1240	−0.0568	0.4964	0.045 (6)*
Cl1	0.0000	0.06226 (5)	0.7500	0.0599 (3)
O1	0.0000	0.2500	0.8704 (7)	0.133 (3)	0.50
H1O	0.0665	0.2321	0.8260	0.199*	0.50
C3	0.1545 (3)	−0.14214 (16)	0.6275 (2)	0.0652 (7)
H3A	0.0923	−0.1178	0.6796	0.081 (5)*
H3B	0.2280	−0.1626	0.6704	0.081 (5)*
H3C	0.1151	−0.1885	0.5866	0.081 (5)*
C2	0.3015 (3)	−0.10914 (18)	0.4605 (2)	0.0719 (8)
H2A	0.3278	−0.0649	0.4084	0.091 (5)*
H2B	0.2664	−0.1559	0.4173	0.091 (5)*
H2C	0.3752	−0.1281	0.5041	0.091 (5)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0414 (13)	0.0469 (14)	0.0379 (15)	0.0043 (11)	0.000	0.000
C1	0.0525 (12)	0.0523 (12)	0.0468 (15)	0.0022 (10)	−0.0081 (10)	−0.0070 (10)
Cl1	0.0600 (5)	0.0545 (5)	0.0653 (6)	0.000	0.0189 (4)	0.000
O1	0.226 (8)	0.065 (4)	0.108 (6)	−0.022 (5)	0.000	0.000
C3	0.0716 (16)	0.0523 (15)	0.0718 (19)	−0.0057 (11)	0.0059 (13)	−0.0030 (12)
C2	0.0871 (18)	0.0680 (16)	0.0606 (19)	0.0048 (14)	0.0102 (14)	−0.0182 (14)

Geometric parameters (Å, º)

N1—C1	1.513 (2)	C3—H3A	0.9600
N1—C1^i	1.513 (2)	C3—H3B	0.9600
C1—C2	1.510 (3)	C3—H3C	0.9600
C1—C3	1.516 (3)	C2—H2A	0.9601
C1—H1A	0.9800	C2—H2B	0.9600
O1—H1O	0.9009	C2—H2C	0.9600
C1—N1—C1^i	117.7 (3)	H3A—C3—H3B	109.5
C2—C1—N1	110.93 (18)	C1—C3—H3C	109.3
C2—C1—C3	112.1 (2)	H3A—C3—H3C	109.5
N1—C1—C3	108.0 (2)	H3B—C3—H3C	109.5
C1—N1—H1	103.9 (14)	C1—C2—H2A	109.6
C1^i—N1—H1	109.8 (15)	C1—C2—H2B	109.5
C2—C1—H1A	108.6	H2A—C2—H2B	109.5
N1—C1—H1A	108.6	C1—C2—H2C	109.4
C3—C1—H1A	108.6	H2A—C2—H2C	109.5
C1—C3—H3A	109.7	H2B—C2—H2C	109.5
C1—C3—H3B	109.4
C1^i—N1—C1—C2	56.61 (17)	C1^i—N1—C1—C3	179.8 (2)

Symmetry code: (i) −x+1/2, −y, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···Cl1	0.90 (1)	2.30 (1)	3.1985 (14)	175 (2)
O1—H1O···O1^ii	0.90	2.39	2.791 (16)	107

Symmetry code: (ii) −x, y, −z+3/2.