1-[(2-Carboxy-1-phenyl­ethyl)iminiomethyl­ene]naphth-2-olate

2-Hydroxy-1-naphthaldehyde condenses with β-phenyl­alanine to form the Schiff base N-(2-hydroxy-1-naphthalidene)-β-phenyl­alanine, which in the solid state exists in the zwitterionic form as (2-carboxy-1-phenyl­ethyl)iminiomethyl­ene-1-naphth-2-olate, C₂₀H₁₇NO₃. The zwitterions are linked by a hydrogen bond from the carboxylic acid group to the negatively charged naphtholate O atom of an adjacent molecule.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.048
• wR factor = 0.127
• Data-to-parameter ratio = 16.2

checkCIF/PLATON results

No syntax errors found



Alert level B
ABSTM02_ALERT_3_B  The ratio of expected to reported Tmax/Tmin(RR') is < 0.75
            Tmin and Tmax reported:      0.641     0.986
            Tmin' and Tmax expected:      0.969     0.986
            RR' =      0.662
            Please check that your absorption correction is appropriate.
PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large .............       0.66

Alert level C
PLAT150_ALERT_1_C Volume as Calculated Differs from that Given ...    3202.00 Ang-3
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?

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

   2 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
   2 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: RAPID-AUTO (Rigaku, 1998); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (Rigaku/MSC, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: SHELXL97.

(2-carboxy-1-phenylethyl)iminiomethylene-1-naphth-2-olate

Crystal data

C20H17NO3	F(000) = 1344
Mr = 319.35	Dx = 1.325 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 12138 reflections
a = 25.152 (5) Å	θ = 3.1–27.5°
b = 9.760 (2) Å	µ = 0.09 mm^−1
c = 15.557 (3) Å	T = 295 K
β = 123.01 (3)°	Prism, yellow
V = 3202 (1) Å^3	0.35 × 0.23 × 0.16 mm
Z = 8

Data collection

Rigaku R-AXIS RAPID diffractometer	3644 independent reflections
Radiation source: fine-focus sealed tube	2488 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
ω scans	θmax = 27.5°, θmin = 3.1°
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	h = −32→31
Tmin = 0.641, Tmax = 0.986	k = −12→12
14977 measured reflections	l = −19→20

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)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.127	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0623P)^2 + 0.5726P] where P = (Fo^2 + 2Fc^2)/3
3644 reflections	(Δ/σ)max = 0.001
225 parameters	Δρmax = 0.23 e Å^−3
2 restraints	Δρmin = −0.17 e Å^−3

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

	x	y	z	Uiso*/Ueq
O1	0.1470 (1)	0.6278 (1)	0.6212 (1)	0.0409 (3)
O2	0.1917 (1)	0.2962 (2)	0.3682 (1)	0.0568 (4)
O3	0.0975 (1)	0.3162 (1)	0.2228 (1)	0.0512 (3)
N1	0.1562 (1)	0.4170 (1)	0.5269 (1)	0.0352 (3)
C1	0.1999 (1)	0.6722 (2)	0.6369 (1)	0.0347 (3)
C2	0.2285 (1)	0.7944 (2)	0.6952 (1)	0.0420 (4)
C3	0.2827 (1)	0.8448 (2)	0.7094 (1)	0.0430 (4)
C4	0.3153 (1)	0.7794 (2)	0.6689 (1)	0.0377 (4)
C5	0.3721 (1)	0.8333 (2)	0.6856 (1)	0.0464 (4)
C6	0.4027 (1)	0.7715 (2)	0.6458 (1)	0.0500 (4)
C7	0.3772 (1)	0.6530 (2)	0.5876 (1)	0.0484 (4)
C8	0.3224 (1)	0.5971 (2)	0.5712 (1)	0.0415 (4)
C9	0.2901 (1)	0.6567 (2)	0.6126 (1)	0.0339 (3)
C10	0.2323 (1)	0.6007 (2)	0.5983 (1)	0.0327 (3)
C11	0.2099 (1)	0.4727 (2)	0.5507 (1)	0.0340 (3)
C12	0.1367 (1)	0.2762 (2)	0.4876 (1)	0.0359 (4)
C13	0.0975 (1)	0.2734 (2)	0.3706 (1)	0.0463 (4)
C14	0.1349 (1)	0.2969 (2)	0.3219 (1)	0.0396 (4)
C15	0.1008 (1)	0.2154 (2)	0.5312 (1)	0.0364 (4)
C16	0.0429 (1)	0.2691 (2)	0.5055 (1)	0.0489 (4)
C17	0.0102 (1)	0.2133 (2)	0.5450 (1)	0.0563 (5)
C18	0.0353 (1)	0.1033 (2)	0.6108 (1)	0.0556 (5)
C19	0.0923 (1)	0.0492 (2)	0.6368 (1)	0.0534 (5)
C20	0.1253 (1)	0.1049 (2)	0.5975 (1)	0.0441 (4)
H3o	0.119 (1)	0.331 (2)	0.195 (1)	0.066 (6)*
H1n	0.135 (1)	0.469 (2)	0.541 (1)	0.055 (6)*
H2	0.2092	0.8401	0.7237	0.050*
H3	0.2995	0.9250	0.7471	0.052*
H5	0.3890	0.9126	0.7244	0.056*
H6	0.4402	0.8082	0.6575	0.060*
H7	0.3976	0.6113	0.5594	0.058*
H8	0.3062	0.5180	0.5319	0.050*
H11	0.2351	0.4237	0.5348	0.041*
H12	0.1751	0.2214	0.5121	0.043*
H13a	0.0764	0.1853	0.3480	0.056*
H13b	0.0648	0.3431	0.3458	0.056*
H16	0.0260	0.3436	0.4612	0.059*
H17	−0.0287	0.2498	0.5273	0.068*
H18	0.0133	0.0657	0.6376	0.067*
H19	0.1089	−0.0253	0.6810	0.064*
H20	0.1642	0.0678	0.6157	0.053*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0436 (6)	0.0482 (7)	0.0432 (6)	0.0023 (5)	0.0317 (5)	−0.0015 (5)
O2	0.0461 (7)	0.0893 (10)	0.0439 (7)	0.0054 (6)	0.0303 (6)	0.0001 (6)
O3	0.0499 (7)	0.0761 (9)	0.0377 (7)	−0.0112 (6)	0.0303 (6)	−0.0028 (5)
N1	0.0390 (7)	0.0381 (8)	0.0378 (7)	−0.0004 (6)	0.0269 (6)	−0.0015 (5)
C1	0.040 (1)	0.038 (1)	0.031 (1)	0.004 (1)	0.022 (1)	0.004 (1)
C2	0.054 (1)	0.041 (1)	0.039 (1)	0.005 (1)	0.031 (1)	−0.003 (1)
C3	0.055 (1)	0.038 (1)	0.037 (1)	−0.003 (1)	0.026 (1)	−0.005 (1)
C4	0.042 (1)	0.039 (1)	0.031 (1)	−0.002 (1)	0.019 (1)	0.001 (1)
C5	0.047 (1)	0.046 (1)	0.041 (1)	−0.010 (1)	0.020 (1)	−0.003 (1)
C6	0.041 (1)	0.060 (1)	0.049 (1)	−0.011 (1)	0.025 (1)	0.001 (1)
C7	0.045 (1)	0.060 (1)	0.051 (1)	−0.003 (1)	0.033 (1)	−0.003 (1)
C8	0.043 (1)	0.045 (1)	0.045 (1)	−0.005 (1)	0.029 (1)	−0.006 (1)
C9	0.036 (1)	0.038 (1)	0.029 (1)	0.001 (1)	0.019 (1)	0.002 (1)
C10	0.036 (1)	0.036 (1)	0.031 (1)	0.001 (1)	0.021 (1)	0.000 (1)
C11	0.036 (1)	0.041 (1)	0.032 (1)	0.001 (1)	0.023 (1)	−0.001 (1)
C12	0.038 (1)	0.039 (1)	0.039 (1)	−0.004 (1)	0.026 (1)	−0.005 (1)
C13	0.048 (1)	0.061 (1)	0.042 (1)	−0.013 (1)	0.032 (1)	−0.009 (1)
C14	0.049 (1)	0.041 (1)	0.039 (1)	−0.004 (1)	0.030 (1)	−0.007 (1)
C15	0.039 (1)	0.044 (1)	0.033 (1)	−0.008 (1)	0.024 (1)	−0.005 (1)
C16	0.044 (1)	0.062 (1)	0.050 (1)	0.001 (1)	0.031 (1)	0.009 (1)
C17	0.044 (1)	0.080 (1)	0.056 (1)	−0.003 (1)	0.034 (1)	0.003 (1)
C18	0.057 (1)	0.073 (1)	0.053 (1)	−0.019 (1)	0.040 (1)	−0.005 (1)
C19	0.066 (1)	0.052 (1)	0.050 (1)	−0.008 (1)	0.036 (1)	0.004 (1)
C20	0.048 (1)	0.045 (1)	0.045 (1)	−0.003 (1)	0.028 (1)	−0.001 (1)

Geometric parameters (Å, º)

O1—C1	1.291 (2)	C16—C17	1.380 (2)
O2—C14	1.201 (2)	C17—C18	1.376 (3)
O3—C14	1.310 (2)	C18—C19	1.366 (3)
N1—C11	1.306 (2)	C19—C20	1.383 (2)
N1—C12	1.475 (2)	O3—H3o	0.86 (1)
C1—C10	1.429 (2)	N1—H1n	0.86 (1)
C1—C2	1.432 (2)	C2—H2	0.93
C2—C3	1.349 (2)	C3—H3	0.93
C3—C4	1.428 (2)	C5—H5	0.93
C4—C5	1.407 (2)	C6—H6	0.93
C4—C9	1.414 (2)	C7—H7	0.93
C5—C6	1.362 (3)	C8—H8	0.93
C6—C7	1.391 (3)	C11—H11	0.93
C7—C8	1.372 (2)	C12—H12	0.98
C8—C9	1.408 (2)	C13—H13a	0.97
C9—C10	1.453 (2)	C13—H13b	0.97
C10—C11	1.405 (2)	C16—H16	0.93
C12—C15	1.514 (2)	C17—H17	0.93
C12—C13	1.527 (2)	C18—H18	0.93
C13—C14	1.512 (2)	C19—H19	0.93
C15—C20	1.383 (2)	C20—H20	0.93
C15—C16	1.387 (2)
C11—N1—C12	124.3 (1)	C14—O3—H3o	112 (1)
O1—C1—C10	121.4 (1)	C11—N1—H1n	113 (1)
O1—C1—C2	120.7 (1)	C12—N1—H1n	123 (1)
C2—C1—C10	117.9 (1)	C3—C2—H2	119.3
C1—C2—C3	121.4 (2)	C1—C2—H2	119.3
C2—C3—C4	122.5 (2)	C2—C3—H3	118.8
C5—C4—C9	119.9 (2)	C4—C3—H3	118.8
C3—C4—C5	121.4 (2)	C6—C5—H5	119.4
C3—C4—C9	118.7 (1)	C4—C5—H5	119.4
C4—C5—C6	121.2 (2)	C5—C6—H6	120.3
C5—C6—C7	119.4 (2)	C7—C6—H6	120.3
C6—C7—C8	120.7 (2)	C8—C7—H7	119.7
C7—C8—C9	121.5 (2)	C6—C7—H7	119.7
C4—C9—C8	117.3 (1)	C7—C8—H8	119.2
C4—C9—C10	119.1 (1)	C9—C8—H8	119.2
C8—C9—C10	123.6 (1)	N1—C11—H11	117.4
C1—C10—C11	119.9 (1)	C10—C11—H11	117.4
C1—C10—C9	120.3 (1)	N1—C12—H12	108.2
C9—C10—C11	119.8 (1)	C15—C12—H12	108.2
N1—C11—C10	125.2 (1)	C13—C12—H12	108.2
N1—C12—C15	109.0 (1)	C14—C13—H13a	108.6
N1—C12—C13	111.3 (1)	C12—C13—H13a	108.6
C13—C12—C15	111.7 (1)	C14—C13—H13b	108.6
C12—C13—C14	114.8 (1)	C12—C13—H13b	108.6
O2—C14—O3	124.2 (2)	H13a—C13—H13b	107.5
O2—C14—C13	124.1 (2)	C17—C16—H16	119.7
O3—C14—C13	111.6 (1)	C15—C16—H16	119.7
C12—C15—C16	120.8 (2)	C18—C17—H17	120.1
C12—C15—C20	120.5 (1)	C16—C17—H17	120.1
C16—C15—C20	118.7 (2)	C19—C18—H18	119.9
C15—C16—C17	120.7 (2)	C17—C18—H18	119.9
C16—C17—C18	119.8 (2)	C18—C19—H19	119.9
C17—C18—C19	120.2 (2)	C20—C19—H19	119.9
C18—C19—C20	120.3 (2)	C15—C20—H20	119.8
C15—C20—C19	120.3 (2)	C19—C20—H20	119.8
O1—C1—C2—C3	−177.8 (1)	C4—C9—C10—C1	2.6 (2)
C10—C1—C2—C3	3.0 (2)	C12—N1—C11—C10	−172.8 (1)
C1—C2—C3—C4	−0.7 (3)	C1—C10—C11—N1	8.4 (2)
C2—C3—C4—C5	−179.5 (2)	C9—C10—C11—N1	−174.7 (1)
C2—C3—C4—C9	−0.7 (2)	C11—N1—C12—C15	143.6 (1)
C9—C4—C5—C6	2.0 (2)	C11—N1—C12—C13	−92.8 (2)
C3—C4—C5—C6	−179.3 (2)	N1—C12—C13—C14	73.3 (2)
C4—C5—C6—C7	0.1 (3)	C15—C12—C13—C14	−164.6 (2)
C5—C6—C7—C8	−1.0 (3)	C12—C13—C14—O2	11.5 (3)
C6—C7—C8—C9	−0.2 (3)	C12—C13—C14—O3	−169.3 (2)
C7—C8—C9—C4	2.2 (2)	N1—C12—C15—C20	−114.7 (2)
C7—C8—C9—C10	−179.4 (2)	C13—C12—C15—C20	121.9 (2)
C5—C4—C9—C8	−3.0 (2)	N1—C12—C15—C16	65.3 (2)
C3—C4—C9—C8	178.2 (1)	C13—C12—C15—C16	−58.1 (2)
C5—C4—C9—C10	178.5 (1)	C20—C15—C16—C17	−0.2 (3)
C3—C4—C9—C10	−0.3 (2)	C12—C15—C16—C17	179.8 (2)
O1—C1—C10—C11	−6.2 (2)	C15—C16—C17—C18	0.2 (3)
C2—C1—C10—C11	173.0 (1)	C16—C17—C18—C19	−0.2 (3)
O1—C1—C10—C9	176.9 (1)	C17—C18—C19—C20	0.2 (3)
C2—C1—C10—C9	−4.0 (2)	C16—C15—C20—C19	0.3 (2)
C8—C9—C10—C11	7.3 (2)	C12—C15—C20—C19	−179.7 (2)
C4—C9—C10—C11	−174.3 (1)	C18—C19—C20—C15	−0.3 (3)
C8—C9—C10—C1	−175.7 (1)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3o···O1^i	0.86 (1)	1.70 (1)	2.547 (2)	169 (2)
N1—H1n···O1	0.86 (1)	1.91 (1)	2.609 (2)	138 (2)

Symmetry code: (i) x, −y+1, z−1/2.