Ammonium L-alanyl-L-phenyl­alaninate

The title compound, NH₄⁺·C₁₂H₁₅N₂O₃^-, was crystallized by slow evaporation of a liquid ammonia solution of L-alanyl-L-phenyl­alanine. The crystal-packing arrangement and the hydrogen-bonding pattern are very similar to those observed for ammonium L-isoleucyl-L-isoleucinate [Görbitz (2004). Acta Cryst. B60, 569-577], the other known ammonium salt of an amino acid or a peptide.

Key indicators

• Single-crystal X-ray study
• T = 105 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.033
• wR factor = 0.082
• Data-to-parameter ratio = 6.9

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.842     0.983
            Tmin' and Tmax expected:      0.966     0.983
            RR' =      0.871
            Please check that your absorption correction is appropriate.
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.87
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       6.94
PLAT480_ALERT_4_C Long H...A H-Bond Reported H11    ..  O3      ..       2.62 Ang.

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.06
           From the CIF: _reflns_number_total               1297
           Count of symmetry unique reflns         1306
           Completeness (_total/calc)             99.31%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present           no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   5 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

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

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Ammonium L-alanyl-L-phenylalaninate

Crystal data

NH4^+·C12H15N2O3^−	F(000) = 272
Mr = 253.30	Dx = 1.257 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 1233 reflections
a = 8.0494 (12) Å	θ = 2.5–25.1°
b = 6.4253 (9) Å	µ = 0.09 mm^−1
c = 12.950 (2) Å	T = 105 K
β = 92.248 (4)°	Block, colourless
V = 669.27 (17) Å^3	0.37 × 0.25 × 0.19 mm
Z = 2

Data collection

Siemens SMART CCD diffractometer	1297 independent reflections
Radiation source: fine-focus sealed tube	1128 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.040
Detector resolution: 8.3 pixels mm^-1	θmax = 25.1°, θmin = 2.5°
Sets of exposures each taken over 0.3° ω rotation scans	h = −9→9
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	k = −7→6
Tmin = 0.842, Tmax = 0.983	l = −6→15
2193 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.033	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.082	H atoms treated by a mixture of independent and constrained refinement
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0513P)^2] where P = (Fo^2 + 2Fc^2)/3
1297 reflections	(Δ/σ)max < 0.001
187 parameters	Δρmax = 0.17 e Å^−3
7 restraints	Δρmin = −0.17 e Å^−3

Special details

Experimental. Crystals grown using NH₃(l) as the solvent.

Refinement. Data were collected by measuring three sets of exposures with the detector set at 2θ = 29°, crystal-to-detector distance 5.00 cm. Refinement of F² against ALL reflections.

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

	x	y	z	Uiso*/Ueq
O1	0.5580 (2)	0.6712 (3)	0.38745 (13)	0.0257 (4)
O2	0.1563 (2)	0.9561 (3)	0.32938 (14)	0.0270 (4)
O3	0.1427 (2)	0.6590 (3)	0.41793 (12)	0.0225 (4)
N1	0.5289 (3)	0.1227 (4)	0.3283 (2)	0.0339 (6)
H1	0.596 (4)	0.007 (6)	0.330 (3)	0.051*
H2	0.461 (4)	0.069 (6)	0.369 (3)	0.051*
N2	0.3772 (3)	0.4814 (4)	0.28944 (16)	0.0204 (5)
H4	0.357 (3)	0.374 (5)	0.264 (2)	0.024*
C1	0.6163 (3)	0.3050 (4)	0.3695 (2)	0.0227 (6)
H11	0.639 (3)	0.293 (5)	0.442 (2)	0.027*
C2	0.7807 (3)	0.3253 (4)	0.3155 (2)	0.0272 (6)
H21	0.8470	0.1992	0.3275	0.041*
H22	0.8420	0.4461	0.3431	0.041*
H23	0.7585	0.3438	0.2411	0.041*
C3	0.5142 (3)	0.5011 (4)	0.34980 (17)	0.0194 (6)
C4	0.2762 (3)	0.6573 (4)	0.25487 (17)	0.0213 (5)
H41	0.3485	0.7603	0.2201	0.026*
C5	0.1398 (3)	0.5824 (5)	0.17705 (19)	0.0283 (6)
H51	0.0651	0.4863	0.2129	0.034*
H52	0.0728	0.7041	0.1538	0.034*
C6	0.2031 (3)	0.4732 (5)	0.08310 (18)	0.0235 (6)
C7	0.3015 (3)	0.5772 (5)	0.01410 (19)	0.0284 (6)
H71	0.3328	0.7174	0.0276	0.034*
C8	0.3545 (4)	0.4802 (6)	−0.0738 (2)	0.0358 (7)
H81	0.4215	0.5539	−0.1203	0.043*
C9	0.3102 (3)	0.2756 (5)	−0.0944 (2)	0.0375 (8)
H91	0.3458	0.2094	−0.1553	0.045*
C10	0.2146 (3)	0.1684 (5)	−0.0263 (2)	0.0345 (7)
H101	0.1847	0.0278	−0.0401	0.041*
C11	0.1615 (3)	0.2657 (5)	0.0624 (2)	0.0286 (6)
H111	0.0965	0.1905	0.1094	0.034*
C12	0.1870 (3)	0.7673 (4)	0.34264 (17)	0.0199 (6)
N1A	0.8477 (3)	0.7501 (4)	0.51525 (16)	0.0210 (5)
H1A	0.850 (4)	0.649 (4)	0.5658 (18)	0.031*
H2A	0.847 (4)	0.876 (4)	0.546 (2)	0.031*
H3A	0.753 (3)	0.727 (5)	0.475 (2)	0.031*
H4A	0.948 (3)	0.733 (5)	0.4819 (19)	0.031*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0251 (9)	0.0211 (10)	0.0305 (9)	0.0016 (8)	−0.0051 (7)	−0.0034 (8)
O2	0.0314 (10)	0.0222 (11)	0.0278 (9)	0.0040 (9)	0.0069 (8)	−0.0005 (8)
O3	0.0235 (9)	0.0229 (9)	0.0218 (9)	0.0025 (8)	0.0078 (7)	0.0006 (8)
N1	0.0279 (13)	0.0184 (13)	0.0564 (16)	−0.0029 (11)	0.0147 (11)	−0.0021 (12)
N2	0.0185 (10)	0.0190 (10)	0.0238 (10)	−0.0013 (10)	0.0027 (8)	−0.0063 (10)
C1	0.0245 (13)	0.0207 (13)	0.0231 (12)	0.0029 (12)	0.0044 (10)	0.0022 (11)
C2	0.0213 (13)	0.0252 (15)	0.0352 (14)	0.0017 (12)	0.0042 (11)	−0.0039 (12)
C3	0.0194 (13)	0.0231 (14)	0.0163 (11)	−0.0024 (11)	0.0065 (10)	0.0009 (11)
C4	0.0173 (11)	0.0249 (13)	0.0220 (12)	0.0015 (12)	0.0034 (9)	−0.0038 (12)
C5	0.0181 (13)	0.0410 (16)	0.0259 (13)	0.0029 (13)	0.0018 (10)	−0.0084 (13)
C6	0.0157 (11)	0.0333 (15)	0.0212 (12)	0.0044 (13)	−0.0019 (10)	−0.0041 (12)
C7	0.0300 (15)	0.0291 (14)	0.0257 (13)	0.0013 (13)	−0.0029 (12)	−0.0013 (12)
C8	0.0318 (15)	0.0523 (19)	0.0234 (13)	0.0036 (16)	0.0026 (11)	0.0006 (14)
C9	0.0305 (15)	0.053 (2)	0.0290 (14)	0.0103 (15)	−0.0009 (12)	−0.0175 (14)
C10	0.0308 (14)	0.0323 (15)	0.0394 (15)	0.0031 (14)	−0.0102 (12)	−0.0130 (14)
C11	0.0234 (13)	0.0324 (16)	0.0298 (13)	−0.0010 (13)	−0.0020 (11)	−0.0017 (13)
C12	0.0150 (11)	0.0228 (15)	0.0220 (12)	0.0006 (11)	−0.0001 (10)	−0.0022 (11)
N1A	0.0177 (10)	0.0230 (11)	0.0224 (11)	−0.0008 (10)	0.0026 (8)	−0.0018 (10)

Geometric parameters (Å, º)

O1—C3	1.242 (3)	C5—C6	1.510 (4)
O2—C12	1.249 (3)	C5—H51	0.9900
O3—C12	1.261 (3)	C5—H52	0.9900
N1—C1	1.457 (3)	C6—C7	1.388 (4)
N1—H1	0.92 (4)	C6—C11	1.398 (4)
N1—H2	0.85 (4)	C7—C8	1.380 (4)
N2—C3	1.333 (3)	C7—H71	0.9500
N2—C4	1.452 (3)	C8—C9	1.386 (5)
N2—H4	0.78 (3)	C8—H81	0.9500
C1—C3	1.520 (3)	C9—C10	1.377 (4)
C1—C2	1.527 (3)	C9—H91	0.9500
C1—H11	0.95 (3)	C10—C11	1.390 (4)
C2—H21	0.9800	C10—H101	0.9500
C2—H22	0.9800	C11—H111	0.9500
C2—H23	0.9800	N1A—H1A	0.92 (2)
C4—C5	1.538 (3)	N1A—H2A	0.90 (2)
C4—C12	1.540 (3)	N1A—H3A	0.92 (2)
C4—H41	1.0000	N1A—H4A	0.94 (2)
C1—N1—H1	112 (2)	C6—C5—H52	108.6
C1—N1—H2	114 (3)	C4—C5—H52	108.6
H1—N1—H2	93 (3)	H51—C5—H52	107.6
C3—N2—C4	123.2 (2)	C7—C6—C11	118.3 (2)
C3—N2—H4	119 (2)	C7—C6—C5	120.9 (3)
C4—N2—H4	117 (2)	C11—C6—C5	120.8 (3)
N1—C1—C3	110.8 (2)	C8—C7—C6	121.1 (3)
N1—C1—C2	108.4 (2)	C8—C7—H71	119.5
C3—C1—C2	108.9 (2)	C6—C7—H71	119.5
N1—C1—H11	111.6 (18)	C7—C8—C9	120.1 (3)
C3—C1—H11	108.3 (18)	C7—C8—H81	119.9
C2—C1—H11	108.9 (16)	C9—C8—H81	119.9
C1—C2—H21	109.5	C10—C9—C8	119.8 (3)
C1—C2—H22	109.5	C10—C9—H91	120.1
H21—C2—H22	109.5	C8—C9—H91	120.1
C1—C2—H23	109.5	C9—C10—C11	120.1 (3)
H21—C2—H23	109.5	C9—C10—H101	119.9
H22—C2—H23	109.5	C11—C10—H101	119.9
O1—C3—N2	121.9 (2)	C10—C11—C6	120.5 (3)
O1—C3—C1	121.3 (2)	C10—C11—H111	119.7
N2—C3—C1	116.7 (2)	C6—C11—H111	119.7
N2—C4—C5	109.6 (2)	O2—C12—O3	125.6 (2)
N2—C4—C12	113.65 (19)	O2—C12—C4	116.1 (2)
C5—C4—C12	106.58 (19)	O3—C12—C4	118.1 (2)
N2—C4—H41	109.0	H1A—N1A—H2A	109 (3)
C5—C4—H41	109.0	H1A—N1A—H3A	106 (3)
C12—C4—H41	109.0	H2A—N1A—H3A	112 (3)
C6—C5—C4	114.7 (2)	H1A—N1A—H4A	104 (3)
C6—C5—H51	108.6	H2A—N1A—H4A	109 (3)
C4—C5—H51	108.6	H3A—N1A—H4A	115 (2)
N1—C1—C3—N2	−7.9 (3)	C12—C4—C5—C6	178.8 (2)
C1—C3—N2—C4	−173.5 (2)	C11—C6—C7—C8	1.3 (4)
C3—N2—C4—C12	−67.3 (3)	C5—C6—C7—C8	−177.6 (2)
N2—C4—C12—O2	152.1 (2)	C6—C7—C8—C9	−0.2 (4)
N2—C4—C5—C6	−57.8 (3)	C7—C8—C9—C10	−0.7 (4)
C4—C5—C6—C7	−62.9 (3)	C8—C9—C10—C11	0.4 (4)
C4—C5—C6—C11	118.2 (3)	C9—C10—C11—C6	0.7 (4)
C4—N2—C3—O1	5.8 (3)	C7—C6—C11—C10	−1.5 (4)
N1—C1—C3—O1	172.8 (2)	C5—C6—C11—C10	177.4 (2)
C2—C1—C3—O1	−68.1 (3)	C5—C4—C12—O2	−87.1 (3)
C2—C1—C3—N2	111.2 (2)	N2—C4—C12—O3	−31.9 (3)
C3—N2—C4—C5	173.7 (2)	C5—C4—C12—O3	88.9 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1^i	0.92 (4)	2.31 (4)	3.007 (3)	133 (3)
N1—H2···O2^i	0.85 (4)	2.59 (4)	3.185 (3)	129 (3)
N2—H4···N1	0.78 (3)	2.27 (3)	2.648 (3)	111 (2)
C1—H11···O3^ii	0.95 (3)	2.62 (3)	3.435 (3)	144 (2)
N1A—H1A···O2^ii	0.92 (2)	1.84 (2)	2.761 (3)	176 (3)
N1A—H2A···O3^iii	0.90 (2)	1.88 (2)	2.766 (3)	168 (3)
N1A—H3A···O1	0.92 (2)	1.93 (2)	2.851 (3)	178 (3)
N1A—H4A···O3^iv	0.94 (2)	1.86 (2)	2.794 (3)	172 (3)

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