2-(Indol-3-yl)ethyl­ammonium dihydrogenphosphate

Ions of the title compound, tryptaminium dihydrogenphosphate, C₁₀H₁₃N₂⁺·H₂PO₄⁻, are connected by inter­molecular N—H...O=P [N...O = 3.028 (3) Å], NH₃...O=P [N...O = 2.720 (3) and 2.950 (3) Å], NH₃...OH—P [N...O = 2.993 (2) Å] and P—OH...O=P [O...O = 2.562 (2) and 2.619 (2) Å] hydrogen bonds between the indole –NH and ammonium —NH₃ groups of the cation and the dihydrogenphosphate anions into an infinite three-dimensional network.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C)= 0.003 Å
• R factor = 0.039
• wR factor = 0.104
• Data-to-parameter ratio = 13.2

checkCIF/PLATON results

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Computing details

Data collection: Siemens R3m/V (Siemens, 1989); cell refinement: Siemens R3m/V; data reduction: XDISK (Siemens, 1989); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-Plus (Sheldrick, 1995); software used to prepare material for publication: SHELXL97.

Tryptaminium dihydrogenphospate

Crystal data

C10H13N2^+·H2O4P^−	F(000) = 1088
Mr = 258.21	Dx = 1.458 Mg m^−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 23 reflections
a = 9.4345 (13) Å	θ = 7.8–12.4°
b = 8.607 (3) Å	µ = 0.24 mm^−1
c = 28.973 (5) Å	T = 294 K
V = 2352.6 (11) Å^3	Prism, colourless
Z = 8	0.49 × 0.40 × 0.34 mm

Data collection

Siemens P4 four-circle diffractometer	1594 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.026
Graphite monochromator	θmax = 25.0°, θmin = 2.6°
Profile fitted scans	h = −1→11
Absorption correction: ψ scan (XPREP in SHELXTL; Sheldrick, 1995)	k = −1→10
Tmin = 0.872, Tmax = 0.921	l = −34→1
2747 measured reflections	3 standard reflections every 97 reflections
2064 independent reflections	intensity decay: 2%

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.039	w = 1/[σ^2(Fo^2) + (0.0524P)^2 + 0.6354P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.104	(Δ/σ)max = 0.002
S = 1.04	Δρmax = 0.30 e Å^−3
2064 reflections	Δρmin = −0.38 e Å^−3
156 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0036 (9)
Primary atom site location: structure-invariant direct methods	Absolute structure: not relevant
Secondary atom site location: difference Fourier map

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
N1	0.0771 (2)	0.1297 (3)	0.60529 (7)	0.0480 (6)
H1	0.1375	0.1304	0.5830	0.058*
C2	−0.0483 (3)	0.0502 (3)	0.60546 (8)	0.0404 (6)
H2	−0.0818	−0.0101	0.5812	0.048*
C3	−0.1173 (2)	0.0721 (3)	0.64636 (7)	0.0327 (5)
C31	−0.2606 (2)	0.0092 (3)	0.65913 (8)	0.0391 (6)
H311	−0.2662	0.0033	0.6925	0.047*
H312	−0.2679	−0.0960	0.6473	0.047*
C32	−0.3874 (2)	0.1014 (3)	0.64176 (7)	0.0349 (5)
H321	−0.4742	0.0481	0.6503	0.042*
H322	−0.3882	0.2030	0.6562	0.042*
N3	−0.3818 (2)	0.1201 (2)	0.59043 (6)	0.0360 (5)
H33	−0.3169	0.1910	0.5832	0.054*
H31	−0.4662	0.1506	0.5801	0.054*
H32	−0.3590	0.0297	0.5775	0.054*
C4	−0.0280 (2)	0.1722 (3)	0.67341 (7)	0.0321 (5)
C5	−0.0369 (3)	0.2359 (3)	0.71807 (8)	0.0429 (6)
H5	−0.1124	0.2112	0.7373	0.051*
C6	0.0683 (3)	0.3351 (3)	0.73271 (10)	0.0558 (8)
H6	0.0623	0.3786	0.7620	0.067*
C7	0.1830 (3)	0.3719 (3)	0.70475 (11)	0.0586 (8)
H7	0.2514	0.4407	0.7156	0.070*
C8	0.1974 (3)	0.3091 (3)	0.66158 (11)	0.0545 (7)
H8	0.2750	0.3328	0.6431	0.065*
C9	0.0915 (2)	0.2082 (3)	0.64634 (8)	0.0397 (6)
P1	0.31209 (5)	0.20594 (6)	0.501410 (18)	0.0254 (2)
O1	0.17781 (15)	0.28496 (17)	0.51743 (6)	0.0343 (4)
O2	0.30519 (17)	0.14730 (19)	0.45298 (5)	0.0368 (4)
O3	0.43299 (16)	0.32758 (18)	0.50901 (6)	0.0375 (4)
H3	0.5097	0.2875	0.5031	0.056*
O4	0.35059 (18)	0.07385 (18)	0.53668 (5)	0.0401 (4)
H4	0.2901	0.0055	0.5356	0.060*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0363 (11)	0.0692 (14)	0.0385 (11)	0.0000 (11)	0.0099 (9)	0.0033 (11)
C2	0.0406 (13)	0.0471 (14)	0.0335 (11)	−0.0006 (12)	−0.0028 (10)	−0.0015 (11)
C3	0.0339 (12)	0.0341 (12)	0.0300 (10)	0.0021 (10)	−0.0018 (9)	0.0058 (10)
C31	0.0389 (13)	0.0409 (13)	0.0375 (12)	−0.0049 (11)	−0.0028 (10)	0.0083 (11)
C32	0.0331 (12)	0.0394 (12)	0.0323 (11)	−0.0043 (10)	0.0028 (10)	−0.0005 (10)
N3	0.0322 (10)	0.0388 (10)	0.0369 (10)	0.0029 (9)	−0.0028 (8)	−0.0013 (8)
C4	0.0311 (12)	0.0335 (12)	0.0319 (11)	0.0045 (10)	−0.0037 (9)	0.0064 (10)
C5	0.0462 (14)	0.0445 (14)	0.0380 (12)	0.0044 (12)	−0.0048 (11)	0.0014 (11)
C6	0.067 (2)	0.0513 (16)	0.0490 (15)	−0.0015 (15)	−0.0192 (14)	−0.0064 (13)
C7	0.0556 (18)	0.0511 (17)	0.0690 (19)	−0.0088 (15)	−0.0283 (16)	0.0033 (15)
C8	0.0350 (14)	0.0620 (18)	0.0666 (18)	−0.0098 (13)	−0.0060 (13)	0.0178 (15)
C9	0.0323 (12)	0.0459 (13)	0.0410 (12)	0.0012 (11)	−0.0038 (10)	0.0097 (11)
P1	0.0197 (3)	0.0259 (3)	0.0306 (3)	−0.0006 (2)	−0.0008 (2)	−0.0012 (2)
O1	0.0217 (8)	0.0348 (8)	0.0465 (9)	0.0014 (7)	0.0024 (7)	−0.0020 (7)
O2	0.0412 (9)	0.0363 (8)	0.0329 (8)	0.0004 (7)	−0.0018 (7)	−0.0040 (7)
O3	0.0222 (8)	0.0364 (8)	0.0538 (10)	−0.0063 (7)	0.0041 (7)	−0.0073 (7)
O4	0.0466 (9)	0.0316 (8)	0.0421 (9)	−0.0009 (8)	−0.0124 (8)	0.0023 (7)

Geometric parameters (Å, º)

N1—C2	1.367 (3)	C4—C9	1.408 (3)
N1—C9	1.375 (3)	C4—C5	1.408 (3)
N1—H1	0.8600	C5—C6	1.376 (4)
C2—C3	1.365 (3)	C5—H5	0.9300
C2—H2	0.9300	C6—C7	1.388 (4)
C3—C4	1.438 (3)	C6—H6	0.9300
C3—C31	1.502 (3)	C7—C8	1.369 (4)
C31—C32	1.522 (3)	C7—H7	0.9300
C31—H311	0.9700	C8—C9	1.396 (4)
C31—H312	0.9700	C8—H8	0.9300
C32—N3	1.497 (3)	P1—O2	1.4927 (16)
C32—H321	0.9700	P1—O1	1.5109 (15)
C32—H322	0.9700	P1—O3	1.5638 (16)
N3—H33	0.8900	P1—O4	1.5712 (16)
N3—H31	0.8900	O3—H3	0.8200
N3—H32	0.8900	O4—H4	0.8200
C2—N1—C9	109.15 (19)	C9—C4—C5	118.3 (2)
C2—N1—H1	125.4	C9—C4—C3	107.32 (19)
C9—N1—H1	125.4	C5—C4—C3	134.4 (2)
C3—C2—N1	110.3 (2)	C6—C5—C4	118.8 (3)
C3—C2—H2	124.8	C6—C5—H5	120.6
N1—C2—H2	124.8	C4—C5—H5	120.6
C2—C3—C4	106.0 (2)	C5—C6—C7	121.6 (3)
C2—C3—C31	126.4 (2)	C5—C6—H6	119.2
C4—C3—C31	127.5 (2)	C7—C6—H6	119.2
C3—C31—C32	115.99 (19)	C8—C7—C6	121.3 (3)
C3—C31—H311	108.3	C8—C7—H7	119.3
C32—C31—H311	108.3	C6—C7—H7	119.3
C3—C31—H312	108.3	C7—C8—C9	117.6 (3)
C32—C31—H312	108.3	C7—C8—H8	121.2
H311—C31—H312	107.4	C9—C8—H8	121.2
N3—C32—C31	110.89 (18)	N1—C9—C8	130.6 (2)
N3—C32—H321	109.5	N1—C9—C4	107.2 (2)
C31—C32—H321	109.5	C8—C9—C4	122.3 (2)
N3—C32—H322	109.5	O2—P1—O1	113.85 (9)
C31—C32—H322	109.5	O2—P1—O3	112.99 (9)
H321—C32—H322	108.0	O1—P1—O3	105.48 (9)
C32—N3—H33	109.5	O2—P1—O4	112.13 (9)
C32—N3—H31	109.5	O1—P1—O4	108.65 (10)
H33—N3—H31	109.5	O3—P1—O4	102.96 (9)
C32—N3—H32	109.5	P1—O3—H3	109.5
H33—N3—H32	109.5	P1—O4—H4	109.5
H31—N3—H32	109.5
C9—N1—C2—C3	−1.1 (3)	C4—C5—C6—C7	−0.8 (4)
N1—C2—C3—C4	0.0 (3)	C5—C6—C7—C8	−1.0 (4)
N1—C2—C3—C31	177.5 (2)	C6—C7—C8—C9	0.9 (4)
C2—C3—C31—C32	−82.1 (3)	C2—N1—C9—C8	−177.1 (3)
C4—C3—C31—C32	95.0 (3)	C2—N1—C9—C4	1.7 (3)
C3—C31—C32—N3	55.8 (3)	C7—C8—C9—N1	179.6 (3)
C2—C3—C4—C9	1.1 (2)	C7—C8—C9—C4	0.9 (4)
C31—C3—C4—C9	−176.5 (2)	C5—C4—C9—N1	178.4 (2)
C2—C3—C4—C5	−179.0 (2)	C3—C4—C9—N1	−1.7 (2)
C31—C3—C4—C5	3.4 (4)	C5—C4—C9—C8	−2.7 (3)
C9—C4—C5—C6	2.5 (3)	C3—C4—C9—C8	177.3 (2)
C3—C4—C5—C6	−177.3 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1	0.86	2.35	3.028 (3)	136
N3—H31···O4^i	0.89	2.24	2.993 (2)	142
N3—H32···O2^ii	0.89	1.83	2.720 (3)	175
N3—H33···O2^iii	0.89	2.09	2.950 (3)	163
O3—H3···O1^iv	0.82	1.80	2.619 (2)	172
O4—H4···O1^v	0.82	1.99	2.562 (2)	126

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