Strong symmetrical intramolecular hydrogen bonds in diprotonated piperazinium bis­(hydrogenmaleate)

In the title salt, C₄H₁₂N₂²⁺·2C₄H₃O₄⁻, the diprotonated piperazine cation links to two hydrogen maleate anions through N—H...O hydrogen bonds. An H atom is approximately centered in an extremely short intramolecular hydrogen bond of the O...H...O type in each of the hydrogen maleate anions.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.042
• wR factor = 0.102
• Data-to-parameter ratio = 13.2

checkCIF results

No syntax errors found



ADDSYM reports no extra symmetry


 Alert Level C:



PLAT_353  Alert C Long    N-H Bond (0.87A)   N(2)   -   H(2B)  =       1.04 Ang.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check

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Computing details

Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: SHELXTL; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Piperazinium bis(Hydrogen maleate)

Crystal data

C4H12N2^2+·2C4H3O4^−	F(000) = 672
Mr = 318.28	Dx = 1.490 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 10.735 (2) Å	Cell parameters from 22 reflections
b = 11.603 (2) Å	θ = 4.0–12.6°
c = 11.843 (2) Å	µ = 0.13 mm^−1
β = 105.87 (1)°	T = 293 K
V = 1418.9 (4) Å^3	Prism, colorless
Z = 4	0.46 × 0.30 × 0.20 mm

Data collection

Siemens P4 diffractometer	Rint = 0.028
Radiation source: fine-focus sealed tube	θmax = 25.5°, θmin = 2.3°
Graphite monochromator	h = 0→13
ω scans	k = 0→14
2775 measured reflections	l = −14→13
2631 independent reflections	3 standard reflections every 97 reflections
1500 reflections with I > 2σ(I)	intensity decay: 1.3%

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)] = 0.042	H-atom parameters constrained
wR(F^2) = 0.102	w = 1/[σ^2(Fo^2) + (0.0698P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.91	(Δ/σ)max < 0.001
2631 reflections	Δρmax = 0.14 e Å^−3
200 parameters	Δρmin = −0.17 e Å^−3
0 restraints	Extinction correction: SHELXTL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0156 (16)

Special details

Experimental. Data collection were performed with a scan width of Δω = (1.0 + 0.30 tan θ)^o and a scan rate of less than 16°min^-1 inω.

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
O1	1.01707 (16)	0.90544 (15)	0.70442 (14)	0.0504 (5)
O2	0.83884 (16)	0.81417 (14)	0.70825 (14)	0.0461 (5)
O3	0.68105 (16)	0.89171 (15)	0.99624 (16)	0.0548 (5)
O4	0.69656 (15)	0.80606 (15)	0.83507 (14)	0.0482 (5)
O5	1.07921 (15)	0.71574 (15)	−0.07079 (14)	0.0493 (5)
O6	1.09071 (16)	0.63470 (15)	−0.23602 (15)	0.0529 (5)
O7	0.93714 (16)	0.70797 (14)	0.05629 (14)	0.0476 (5)
O8	0.76236 (17)	0.61331 (16)	0.06466 (14)	0.0524 (5)
N1	0.98012 (17)	0.76114 (16)	0.50401 (15)	0.0354 (5)
N2	0.80103 (17)	0.72217 (16)	0.27844 (15)	0.0362 (5)
C1	0.9245 (2)	0.8922 (2)	0.7458 (2)	0.0383 (6)
C2	0.9124 (2)	0.9718 (2)	0.84063 (19)	0.0414 (6)
H2	0.9691	1.0341	0.8538	0.050*
C3	0.8331 (2)	0.9680 (2)	0.9098 (2)	0.0402 (6)
H3	0.8435	1.0281	0.9636	0.048*
C4	0.7306 (2)	0.8833 (2)	0.9148 (2)	0.0397 (6)
C5	1.0403 (2)	0.6429 (2)	−0.1548 (2)	0.0398 (6)
C6	0.9308 (2)	0.5653 (2)	−0.1553 (2)	0.0433 (6)
H6	0.9135	0.5102	−0.2147	0.052*
C7	0.8529 (2)	0.5609 (2)	−0.0853 (2)	0.0436 (6)
H7	0.7899	0.5037	−0.1043	0.052*
C8	0.8496 (2)	0.6319 (2)	0.0180 (2)	0.0385 (6)
C9	0.9382 (2)	0.8570 (2)	0.4191 (2)	0.0417 (6)
H9A	1.0078	0.9127	0.4294	0.050*
H9B	0.8642	0.8956	0.4340	0.050*
C10	0.9025 (2)	0.8124 (2)	0.29493 (19)	0.0393 (6)
H10A	0.8710	0.8755	0.2409	0.047*
H10B	0.9787	0.7805	0.2775	0.047*
C11	0.8422 (2)	0.6266 (2)	0.36360 (18)	0.0410 (6)
H11A	0.9162	0.5876	0.3489	0.049*
H11B	0.7724	0.5711	0.3531	0.049*
C12	0.8781 (2)	0.6714 (2)	0.48857 (19)	0.0388 (6)
H12A	0.8021	0.7038	0.5059	0.047*
H12B	0.9094	0.6083	0.5427	0.047*
H2'	1.0128	0.7165	−0.0007	0.080*
H1'	0.7626	0.8049	0.7663	0.080*
H1A	1.0576	0.7292	0.5008	0.080*
H2B	0.7933	0.6886	0.1958	0.080*
H2A	0.7219	0.7587	0.2816	0.080*
H1B	0.9951	0.7949	0.5823	0.080*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0585 (12)	0.0542 (11)	0.0475 (11)	−0.0025 (10)	0.0295 (10)	0.0016 (9)
O2	0.0465 (10)	0.0500 (11)	0.0414 (10)	−0.0044 (9)	0.0116 (8)	−0.0120 (8)
O3	0.0515 (11)	0.0524 (11)	0.0741 (13)	−0.0057 (9)	0.0400 (10)	−0.0088 (10)
O4	0.0391 (10)	0.0529 (11)	0.0531 (11)	−0.0110 (9)	0.0137 (8)	−0.0082 (9)
O5	0.0410 (10)	0.0585 (12)	0.0484 (10)	−0.0161 (9)	0.0124 (8)	−0.0099 (9)
O6	0.0466 (11)	0.0613 (12)	0.0582 (12)	−0.0006 (9)	0.0267 (10)	−0.0037 (9)
O7	0.0476 (10)	0.0535 (11)	0.0412 (10)	−0.0093 (9)	0.0116 (8)	−0.0143 (8)
O8	0.0540 (11)	0.0684 (13)	0.0404 (10)	−0.0087 (10)	0.0226 (9)	−0.0029 (9)
N1	0.0326 (10)	0.0403 (11)	0.0333 (10)	−0.0009 (9)	0.0090 (8)	−0.0046 (9)
N2	0.0312 (10)	0.0445 (12)	0.0331 (11)	0.0002 (9)	0.0089 (8)	−0.0043 (9)
C1	0.0435 (15)	0.0407 (14)	0.0305 (13)	0.0049 (12)	0.0097 (11)	0.0073 (11)
C2	0.0393 (14)	0.0429 (15)	0.0423 (14)	−0.0064 (12)	0.0119 (12)	−0.0066 (12)
C3	0.0376 (14)	0.0411 (15)	0.0428 (14)	−0.0049 (12)	0.0123 (12)	−0.0083 (12)
C4	0.0324 (13)	0.0388 (14)	0.0489 (15)	0.0050 (12)	0.0128 (12)	0.0032 (12)
C5	0.0342 (13)	0.0390 (14)	0.0461 (15)	0.0045 (12)	0.0105 (12)	0.0030 (13)
C6	0.0461 (16)	0.0458 (15)	0.0386 (14)	−0.0078 (13)	0.0124 (12)	−0.0108 (12)
C7	0.0433 (15)	0.0454 (15)	0.0420 (14)	−0.0150 (13)	0.0117 (12)	−0.0097 (12)
C8	0.0390 (14)	0.0423 (14)	0.0326 (13)	−0.0008 (13)	0.0070 (11)	0.0014 (11)
C9	0.0437 (15)	0.0336 (13)	0.0477 (15)	−0.0041 (12)	0.0123 (12)	−0.0005 (12)
C10	0.0393 (14)	0.0403 (14)	0.0399 (14)	−0.0005 (12)	0.0136 (11)	0.0066 (11)
C11	0.0414 (15)	0.0366 (14)	0.0425 (14)	−0.0064 (12)	0.0073 (12)	−0.0013 (12)
C12	0.0423 (14)	0.0381 (14)	0.0370 (13)	−0.0021 (11)	0.0123 (11)	0.0046 (11)

Geometric parameters (Å, º)

O2—H1'	1.21	C1—C2	1.486 (3)
O7—H2'	1.19	C2—C3	1.334 (3)
O4—H1'	1.22	C2—H2	0.9300
O5—H2'	1.23	C3—C4	1.489 (3)
O1—C1	1.232 (3)	C3—H3	0.9300
O3—C4	1.226 (3)	C5—C6	1.479 (3)
O6—C5	1.230 (3)	C6—C7	1.330 (3)
O8—C8	1.230 (3)	C6—H6	0.9300
O2—C1	1.281 (3)	C7—C8	1.484 (3)
O4—C4	1.281 (3)	C7—H7	0.9300
O5—C5	1.285 (3)	C9—C10	1.506 (3)
O7—C8	1.279 (3)	C9—H9A	0.9700
N1—C9	1.484 (3)	C9—H9B	0.9700
N1—C12	1.486 (3)	C10—H10A	0.9700
N1—H1A	0.92	C10—H10B	0.9700
N1—H1B	0.98	C11—C12	1.516 (3)
N2—C11	1.483 (3)	C11—H11A	0.9700
N2—C10	1.485 (3)	C11—H11B	0.9700
N2—H2B	1.04	C12—H12A	0.9700
N2—H2A	0.96	C12—H12B	0.9700
C1—O2—H1'	113.50	C3—C2—H2	114.9
C4—O4—H1'	113.59	C1—C2—H2	114.9
C5—O5—H2'	113.57	C2—C3—H3	114.8
C8—O7—H2'	113.86	C4—C3—H3	114.8
C9—N1—C12	111.42 (17)	C7—C6—H6	114.6
C9—N1—H1A	112.53	C5—C6—H6	114.6
C12—N1—H1A	110.90	C6—C7—H7	114.6
C9—N1—H1B	106.44	C8—C7—H7	114.6
C12—N1—H1B	108.77	N1—C9—C10	110.69 (18)
H1A—N1—H1B	106.50	N1—C9—H9A	109.5
C11—N2—C10	111.49 (17)	C10—C9—H9A	109.5
C11—N2—H2B	107.06	N1—C9—H9B	109.5
C10—N2—H2B	104.83	C10—C9—H9B	109.5
C11—N2—H2A	113.98	H9A—C9—H9B	108.1
C10—N2—H2A	108.00	N2—C10—C9	110.64 (18)
H2B—N2—H2A	111.11	N2—C10—H10A	109.5
O1—C1—O2	122.0 (2)	C9—C10—H10A	109.5
O1—C1—C2	118.0 (2)	N2—C10—H10B	109.5
O2—C1—C2	119.9 (2)	C9—C10—H10B	109.5
O8—C8—O7	122.6 (2)	H10A—C10—H10B	108.1
O8—C8—C7	117.8 (2)	N2—C11—C12	110.90 (18)
O7—C8—C7	119.7 (2)	N2—C11—H11A	109.5
O3—C4—O4	122.5 (2)	C12—C11—H11A	109.5
O3—C4—C3	117.6 (2)	N2—C11—H11B	109.5
O4—C4—C3	119.8 (2)	C12—C11—H11B	109.5
O6—C5—O5	122.4 (2)	H11A—C11—H11B	108.0
O6—C5—C6	117.9 (2)	N1—C12—C11	110.00 (18)
O5—C5—C6	119.6 (2)	N1—C12—H12A	109.7
C3—C2—C1	130.2 (2)	C11—C12—H12A	109.7
C6—C7—C8	130.8 (2)	N1—C12—H12B	109.7
C2—C3—C4	130.5 (2)	C11—C12—H12B	109.7
C7—C6—C5	130.9 (2)	H12A—C12—H12B	108.2
O1—C1—C2—C3	−170.5 (2)	C6—C7—C8—O8	176.5 (3)
O2—C1—C2—C3	10.7 (4)	C6—C7—C8—O7	−4.5 (4)
C1—C2—C3—C4	−0.1 (4)	C12—N1—C9—C10	−57.2 (2)
C2—C3—C4—O3	171.6 (3)	C11—N2—C10—C9	−56.1 (2)
C2—C3—C4—O4	−9.1 (4)	N1—C9—C10—N2	56.1 (2)
O6—C5—C6—C7	−174.2 (3)	C10—N2—C11—C12	56.3 (2)
O5—C5—C6—C7	5.8 (4)	C9—N1—C12—C11	56.8 (2)
C5—C6—C7—C8	−0.5 (5)	N2—C11—C12—N1	−56.1 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1′···O4	1.21	1.22	2.419 (2)	171
O7—H2′···O5	1.19	1.23	2.420 (2)	171
N1—H1B···O1	0.98	1.90	2.842 (2)	161
N2—H2B···O8	1.04	1.73	2.757 (2)	169
N1—H1A···O3^i	0.92	1.94	2.813 (3)	157
N2—H2A···O6^ii	0.96	1.84	2.770 (3)	162
C10—H10B···O4^i	0.97	2.46	3.356 (3)	153
C12—H12A···O5^ii	0.97	2.50	3.357 (3)	148

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