Crystal structure of a (carb­oxy­meth­yl)tri­ethyl­aza­nium bromide–2-(tri­ethyl­aza­n­ium­yl)acetate (1/1) hydrogen-bonded dimer

The crystal structure of a hydrogen-bonded dimer of (tri­ethyl­azaniumyl)­acetic acid and (tri­ethyl­azaniumyl)­acetate bromide features a carb­oxy­lic acid hydrogen atom that is engaged in an asymmetric hydrogen bond with the carboxyl­ate oxygen. The crystal also features intra­molecular C—H hydrogen bonds and a layer of bromide ions that is surrounded by alkyl groups.

Key indicators

Structure: I

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.040
• wR factor = 0.109
• Data-to-parameter ratio = 18.3

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full value Low .      0.979 Why?
PLAT042_ALERT_1_C Calc. and Reported MoietyFormula Strings  Differ     Please Check
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.14 Report
PLAT911_ALERT_3_C Missing FCF Refl Between Thmin & STh/L=    0.600         38 Report

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   C16 H35 Br1 N2 O4
            Atom count from _chemical_formula_moiety:C64 H136 N16 O32
PLAT007_ALERT_5_G Number of Unrefined Donor-H Atoms ..............          1 Report
PLAT093_ALERT_1_G No s.u.'s on H-positions, Refinement Reported as      mixed Check
PLAT300_ALERT_4_G Atom Site Occupancy of H1         Constrained at        0.5 Check
PLAT789_ALERT_4_G Atoms with Negative _atom_site_disorder_group  #         28 Check
PLAT802_ALERT_4_G CIF Input Record(s) with more than 80 Characters          3 Info
PLAT822_ALERT_4_G CIF-embedded .res Contains Negative PART Numbers          1 Check
PLAT883_ALERT_1_G No Info/Value for _atom_sites_solution_primary .     Please Do !
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         96 Note
PLAT913_ALERT_3_G Missing # of Very Strong Reflections in FCF ....          1 Note
PLAT941_ALERT_3_G Average HKL Measurement Multiplicity ...........        3.1 Low
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density.          2 Info

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   4 ALERT level C = Check. Ensure it is not caused by an omission or oversight
  12 ALERT level G = General information/check it is not something unexpected

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   5 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

---

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2006); cell refinement: CrysAlis PRO (Oxford Diffraction, 2006); data reduction: CrysAlis PRO (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: CrystalMaker (Palmer, 2007); software used to prepare material for publication: Olex2 (Dolomanov et al., 2009; Bourhis et al., 2015).

(Carboxymethyl)triethylazanium bromide–2-(triethylazaniumyl)acetate (1/1)

Crystal data

C8H18NO2^+·Br^−·C8H17NO2	F(000) = 848
Mr = 399.37	Dx = 1.355 Mg m^−3
Monoclinic, I2/a	Cu Kα radiation, λ = 1.54184 Å
a = 12.6692 (4) Å	Cell parameters from 3269 reflections
b = 7.0967 (3) Å	θ = 6.6–79.4°
c = 22.3413 (9) Å	µ = 3.03 mm^−1
β = 103.022 (4)°	T = 100 K
V = 1957.04 (13) Å^3	Plate, colourless
Z = 4	0.42 × 0.13 × 0.02 mm

Data collection

XtaLAB Synergy, Dualflex, HyPix diffractometer	1785 reflections with I > 2σ(I)
Detector resolution: 10.0000 pixels mm^-1	Rint = 0.052
ω scans	θmax = 80.0°, θmin = 4.1°
Absorption correction: gaussian (CrysAlisPro; Oxford Diffraction, 2006)	h = −11→16
Tmin = 0.568, Tmax = 1.000	k = −8→8
6198 measured reflections	l = −28→25
1998 independent reflections

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Hydrogen site location: mixed
R[F^2 > 2σ(F^2)] = 0.040	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.109	w = 1/[σ^2(Fo^2) + (0.0638P)^2 + 1.4873P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
1998 reflections	Δρmax = 0.89 e Å^−3
109 parameters	Δρmin = −0.42 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
Br1	0.250000	0.39582 (5)	0.500000	0.01824 (16)
O1	0.70415 (15)	0.3474 (3)	0.28191 (9)	0.0250 (4)
H1	0.734798	0.280169	0.252098	0.07 (3)*	0.5
O2	0.57904 (15)	0.1209 (3)	0.27312 (9)	0.0235 (4)
N1	0.49061 (15)	0.3014 (3)	0.36825 (9)	0.0146 (4)
C1	0.61984 (19)	0.2698 (4)	0.29428 (11)	0.0181 (5)
C2	0.57456 (19)	0.3923 (3)	0.33887 (12)	0.0155 (5)
H2A	0.635817	0.434190	0.372016	0.019*
H2B	0.542009	0.506334	0.316589	0.019*
C3	0.5279 (2)	0.1112 (3)	0.39641 (12)	0.0187 (5)
H3A	0.522278	0.017911	0.362887	0.022*
H3B	0.477980	0.070888	0.422252	0.022*
C4	0.6431 (2)	0.1076 (4)	0.43539 (14)	0.0242 (6)
H4A	0.694224	0.132344	0.409276	0.036*
H4B	0.658203	−0.016535	0.454658	0.036*
H4C	0.651144	0.204548	0.467320	0.036*
C5	0.47364 (19)	0.4306 (4)	0.41955 (11)	0.0168 (5)
H5A	0.419692	0.371758	0.439611	0.020*
H5B	0.542724	0.439647	0.450705	0.020*
C6	0.4358 (2)	0.6278 (4)	0.39983 (14)	0.0255 (6)
H6A	0.369669	0.621107	0.367223	0.038*
H6B	0.492434	0.693461	0.384459	0.038*
H6C	0.420881	0.696650	0.435042	0.038*
C7	0.38591 (18)	0.2757 (4)	0.31950 (11)	0.0170 (5)
H7A	0.360683	0.400804	0.302461	0.020*
H7B	0.401558	0.198822	0.285550	0.020*
C8	0.2954 (2)	0.1824 (4)	0.34289 (13)	0.0242 (6)
H8A	0.228952	0.182944	0.310402	0.036*
H8B	0.283092	0.251692	0.378634	0.036*
H8C	0.315681	0.052079	0.354755	0.036*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0155 (2)	0.0211 (2)	0.0191 (2)	0.000	0.00614 (14)	0.000
O1	0.0209 (9)	0.0313 (10)	0.0264 (10)	−0.0062 (8)	0.0132 (8)	−0.0083 (8)
O2	0.0214 (9)	0.0270 (10)	0.0242 (10)	−0.0037 (7)	0.0091 (8)	−0.0089 (7)
N1	0.0128 (8)	0.0161 (10)	0.0154 (10)	−0.0009 (7)	0.0043 (8)	0.0001 (8)
C1	0.0161 (10)	0.0229 (13)	0.0149 (12)	0.0010 (9)	0.0029 (9)	−0.0013 (9)
C2	0.0138 (10)	0.0171 (12)	0.0162 (12)	−0.0029 (8)	0.0050 (9)	−0.0002 (9)
C3	0.0212 (12)	0.0158 (12)	0.0186 (12)	0.0001 (8)	0.0035 (10)	0.0024 (9)
C4	0.0213 (12)	0.0252 (14)	0.0233 (14)	0.0057 (10)	−0.0010 (10)	0.0019 (10)
C5	0.0151 (10)	0.0214 (12)	0.0140 (11)	0.0015 (9)	0.0033 (9)	−0.0002 (9)
C6	0.0315 (14)	0.0214 (14)	0.0255 (15)	0.0075 (10)	0.0107 (12)	0.0003 (10)
C7	0.0136 (9)	0.0218 (12)	0.0145 (11)	−0.0025 (9)	0.0008 (9)	−0.0003 (9)
C8	0.0159 (11)	0.0331 (15)	0.0231 (13)	−0.0068 (10)	0.0032 (10)	−0.0005 (11)

Geometric parameters (Å, º)

O1—H1	0.9686	C4—H4B	0.9800
O1—C1	1.286 (3)	C4—H4C	0.9800
O2—C1	1.224 (3)	C5—H5A	0.9900
N1—C2	1.514 (3)	C5—H5B	0.9900
N1—C3	1.519 (3)	C5—C6	1.512 (4)
N1—C5	1.520 (3)	C6—H6A	0.9800
N1—C7	1.526 (3)	C6—H6B	0.9800
C1—C2	1.528 (3)	C6—H6C	0.9800
C2—H2A	0.9900	C7—H7A	0.9900
C2—H2B	0.9900	C7—H7B	0.9900
C3—H3A	0.9900	C7—C8	1.515 (3)
C3—H3B	0.9900	C8—H8A	0.9800
C3—C4	1.522 (4)	C8—H8B	0.9800
C4—H4A	0.9800	C8—H8C	0.9800
C1—O1—H1	114.7	H4A—C4—H4C	109.5
C2—N1—C3	112.00 (18)	H4B—C4—H4C	109.5
C2—N1—C5	107.61 (18)	N1—C5—H5A	108.4
C2—N1—C7	108.91 (18)	N1—C5—H5B	108.4
C3—N1—C5	107.89 (19)	H5A—C5—H5B	107.5
C3—N1—C7	109.20 (19)	C6—C5—N1	115.3 (2)
C5—N1—C7	111.24 (17)	C6—C5—H5A	108.4
O1—C1—C2	110.4 (2)	C6—C5—H5B	108.4
O2—C1—O1	125.8 (2)	C5—C6—H6A	109.5
O2—C1—C2	123.7 (2)	C5—C6—H6B	109.5
N1—C2—C1	116.35 (19)	C5—C6—H6C	109.5
N1—C2—H2A	108.2	H6A—C6—H6B	109.5
N1—C2—H2B	108.2	H6A—C6—H6C	109.5
C1—C2—H2A	108.2	H6B—C6—H6C	109.5
C1—C2—H2B	108.2	N1—C7—H7A	108.7
H2A—C2—H2B	107.4	N1—C7—H7B	108.7
N1—C3—H3A	108.5	H7A—C7—H7B	107.6
N1—C3—H3B	108.5	C8—C7—N1	114.2 (2)
N1—C3—C4	114.9 (2)	C8—C7—H7A	108.7
H3A—C3—H3B	107.5	C8—C7—H7B	108.7
C4—C3—H3A	108.5	C7—C8—H8A	109.5
C4—C3—H3B	108.5	C7—C8—H8B	109.5
C3—C4—H4A	109.5	C7—C8—H8C	109.5
C3—C4—H4B	109.5	H8A—C8—H8B	109.5
C3—C4—H4C	109.5	H8A—C8—H8C	109.5
H4A—C4—H4B	109.5	H8B—C8—H8C	109.5
O1—C1—C2—N1	−167.3 (2)	C3—N1—C7—C8	56.4 (3)
O2—C1—C2—N1	13.8 (4)	C5—N1—C2—C1	168.8 (2)
C2—N1—C3—C4	46.5 (3)	C5—N1—C3—C4	−71.8 (3)
C2—N1—C5—C6	59.1 (3)	C5—N1—C7—C8	−62.6 (3)
C2—N1—C7—C8	179.0 (2)	C7—N1—C2—C1	−70.5 (3)
C3—N1—C2—C1	50.4 (3)	C7—N1—C3—C4	167.2 (2)
C3—N1—C5—C6	−179.9 (2)	C7—N1—C5—C6	−60.1 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O1^i	0.97	1.50	2.457 (4)	167
C3—H3A···O2	0.99	2.39	2.969 (3)	116
C7—H7B···O2	0.99	2.39	3.068 (3)	125

Symmetry code: (i) −x+3/2, −y+1/2, −z+1/2.