Dimethyl 2-amino­biphenyl-4,4′-di­carboxyl­ate

The title compound, C₁₆H₁₅NO₄, exhibits two near-planar aromatic ester groups with a maximum aryl–ester torsion angle of 1.9 (2)°. The dihedral angle between the benzene rings is 44.7 (1)°. In the crystal, N—H...O hydrogen bonding is observed along with C—H...O contacts, forming chanins along [101]. No π–π inter­actions were noted between the benzene rings.

Key indicators

• Single-crystal X-ray study
• T = 90 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.045
• wR factor = 0.124
• Data-to-parameter ratio = 12.4

checkCIF/PLATON results

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Datablock: I


Alert level C
PLAT230_ALERT_2_C Hirshfeld Test Diff for    N1     --  C5      ..        6.6 su
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          2
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         13

Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          3
PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels ..........          2
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          2
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600         12

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

   0 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
   3 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Biphenyl-4,4'-dicarboxylate and its derivatives are widely used in metal-organic (MOFs) frameworks as linkers (Sudik et al. 2005). One of the many advantages of MOFs is the ability to incorporate different functional groups within their pores. An area of interest is the inclusion of open Lewis base sites on the interior surfaces of MOFs. As a part of our efforts in this field, we prepared the previously reported dimethyl-2-aminobiphenyl-4,4'-dicarboxylate (Olkhovik et al. 2008) and report its structure herein.

The molecular structure of the title compound is shown in Figure 1. The two phenyl rings demonstrate a dihedral angle of 135.3°. In the crystal, intermolecular hydrogen bonding is observed between N1–H1NA···O4 and N1H1NB···O2. There is also a close C–H···O contact along C4H4A···O2. No π-π interactions were noted between the phenyl rings. The packing for the title compound indicating hydrogen bonding is shown in Figure 2.

Related literature

For the synthesis of the title compound, see: Olkhovik et al. (2008). For the crystal structures of the parent dimethyl-4,4'-dicarboxylate and its structurally characterized amino derivatives, see: Ritzerfeld et al. (2009); Nyburg et al. (1988). For metal-organic framework structures with this and related linkers, see: Deshpande et al. (2010); Lun et al. (2011); Gupta et al. (2012); Sudik et al. (2005).

S2. Experimental

The compound was prepared by literature procedure (Olkhovik et al. 2008). Crystals suitable for single-crystal X-ray analysis were grown by slow evaporation of an ethanol solution.

S3. Refinement

All non-hydrogen atoms were refined anisotropically (SHELXL) by full matrix least squares on F². Hydrogen atoms H1NA and H1NB were found from a Fourier difference map and were refined with fixed distance of 0.87 (005) Å and isotropic displacement parameter of 1.20 times U_eq of parent N atom. All other hydrogen atoms were placed in calculated positions and then refined with riding model with C—H lengths of 0.95 Å for (CH) and 0.98 Å for (CH₃) and with isotropic displacement parameters set to 1.20 and 1.50 times U_eq of the parent C atom.

Computing details

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures

	Fig. 1. Molecular structure of the title compound, showing the atom labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are presented as spheres of arbitrary radius.
	Fig. 2. Molecular packing of the title compound with hydrogen bonding shown as dashed lines.

Dimethyl 2-aminobiphenyl-4,4'-dicarboxylate

Crystal data

C16H15NO4	F(000) = 600
Mr = 285.29	Dx = 1.418 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2401 reflections
a = 12.955 (3) Å	θ = 2.9–24.9°
b = 7.3460 (16) Å	µ = 0.10 mm^−1
c = 14.422 (3) Å	T = 90 K
β = 103.263 (10)°	Plate, colourless
V = 1336.0 (5) Å^3	0.28 × 0.12 × 0.06 mm
Z = 4

Data collection

Bruker APEXII CCD diffractometer	2463 independent reflections
Radiation source: fine-focus sealed tube	1785 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.036
φ and ω scans	θmax = 25.5°, θmin = 3.0°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −15→15
Tmin = 0.972, Tmax = 0.994	k = −8→8
9113 measured reflections	l = −17→17

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.124	H atoms treated by a mixture of independent and constrained refinement
S = 1.01	w = 1/[σ^2(Fo^2) + (0.0609P)^2 + 0.6328P] where P = (Fo^2 + 2Fc^2)/3
2463 reflections	(Δ/σ)max < 0.001
198 parameters	Δρmax = 0.27 e Å^−3
2 restraints	Δρmin = −0.35 e Å^−3

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
O1	0.06313 (12)	0.5135 (2)	−0.10419 (10)	0.0276 (4)
O2	−0.00179 (13)	0.7915 (2)	−0.09219 (11)	0.0351 (4)
O3	0.71122 (11)	0.6353 (2)	0.53463 (9)	0.0237 (4)
O4	0.61240 (12)	0.7629 (2)	0.62568 (10)	0.0280 (4)
N1	0.22094 (16)	1.0226 (3)	0.21975 (14)	0.0321 (5)
H1NB	0.1839 (17)	1.109 (2)	0.1855 (15)	0.038*
H1NA	0.2785 (12)	1.051 (3)	0.2629 (13)	0.038*
C1	−0.00925 (17)	0.4946 (3)	−0.19589 (14)	0.0277 (5)
H1C	−0.0122	0.3668	−0.2157	0.042*
H1B	0.0153	0.5695	−0.2428	0.042*
H1A	−0.0801	0.5349	−0.1915	0.042*
C2	0.06020 (17)	0.6717 (3)	−0.05967 (15)	0.0215 (5)
C3	0.14017 (16)	0.6815 (3)	0.03194 (14)	0.0201 (5)
C4	0.14580 (16)	0.8404 (3)	0.08492 (14)	0.0205 (5)
H4A	0.0976	0.9367	0.0624	0.025*
C5	0.22104 (16)	0.8614 (3)	0.17076 (14)	0.0190 (5)
C6	0.29167 (16)	0.7167 (3)	0.20412 (14)	0.0181 (5)
C7	0.28276 (16)	0.5577 (3)	0.14953 (14)	0.0206 (5)
H7A	0.3294	0.4592	0.1719	0.025*
C8	0.20895 (17)	0.5381 (3)	0.06445 (14)	0.0212 (5)
H8A	0.2052	0.4286	0.0287	0.025*
C9	0.37584 (16)	0.7249 (3)	0.29319 (14)	0.0188 (5)
C10	0.35757 (16)	0.7869 (3)	0.37973 (14)	0.0198 (5)
H10A	0.2899	0.8339	0.3819	0.024*
C11	0.43708 (17)	0.7805 (3)	0.46212 (14)	0.0209 (5)
H11A	0.4235	0.8229	0.5204	0.025*
C12	0.53657 (16)	0.7127 (3)	0.46029 (14)	0.0188 (5)
C13	0.55552 (17)	0.6511 (3)	0.37448 (14)	0.0211 (5)
H13A	0.6233	0.6040	0.3725	0.025*
C14	0.47657 (16)	0.6582 (3)	0.29247 (14)	0.0215 (5)
H14A	0.4909	0.6170	0.2342	0.026*
C15	0.62115 (16)	0.7076 (3)	0.54930 (15)	0.0198 (5)
C16	0.79774 (17)	0.6225 (3)	0.61760 (15)	0.0258 (5)
H16A	0.8590	0.5660	0.5999	0.039*
H16B	0.7760	0.5480	0.6662	0.039*
H16C	0.8170	0.7446	0.6431	0.039*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0266 (9)	0.0302 (9)	0.0209 (8)	0.0058 (7)	−0.0052 (7)	−0.0085 (7)
O2	0.0427 (10)	0.0261 (9)	0.0284 (9)	0.0092 (8)	−0.0087 (8)	−0.0008 (7)
O3	0.0201 (8)	0.0284 (8)	0.0188 (8)	0.0022 (7)	−0.0030 (6)	−0.0014 (6)
O4	0.0283 (9)	0.0359 (9)	0.0183 (8)	0.0000 (7)	0.0019 (7)	−0.0053 (7)
N1	0.0321 (12)	0.0302 (11)	0.0304 (12)	0.0010 (9)	−0.0001 (9)	−0.0020 (9)
C1	0.0267 (12)	0.0343 (13)	0.0168 (11)	0.0013 (10)	−0.0059 (9)	−0.0066 (9)
C2	0.0238 (11)	0.0199 (11)	0.0203 (11)	0.0008 (9)	0.0038 (9)	0.0003 (9)
C3	0.0204 (11)	0.0224 (11)	0.0171 (11)	−0.0025 (9)	0.0033 (9)	−0.0003 (9)
C4	0.0203 (11)	0.0193 (10)	0.0213 (11)	0.0015 (9)	0.0035 (9)	0.0018 (9)
C5	0.0204 (11)	0.0201 (11)	0.0175 (10)	−0.0030 (9)	0.0062 (9)	−0.0013 (9)
C6	0.0166 (10)	0.0229 (11)	0.0155 (10)	−0.0017 (9)	0.0052 (9)	0.0000 (8)
C7	0.0196 (11)	0.0210 (11)	0.0205 (11)	0.0022 (9)	0.0032 (9)	0.0002 (9)
C8	0.0234 (11)	0.0201 (11)	0.0197 (11)	0.0001 (9)	0.0037 (9)	−0.0026 (9)
C9	0.0209 (11)	0.0168 (10)	0.0176 (10)	−0.0035 (9)	0.0019 (9)	−0.0006 (8)
C10	0.0191 (11)	0.0207 (11)	0.0191 (11)	−0.0001 (9)	0.0036 (9)	−0.0021 (9)
C11	0.0251 (12)	0.0202 (11)	0.0177 (11)	0.0001 (9)	0.0055 (9)	−0.0028 (8)
C12	0.0205 (11)	0.0163 (10)	0.0181 (11)	−0.0032 (9)	0.0014 (9)	0.0014 (8)
C13	0.0187 (11)	0.0243 (12)	0.0202 (11)	0.0001 (9)	0.0044 (9)	−0.0008 (9)
C14	0.0218 (11)	0.0274 (12)	0.0162 (10)	−0.0021 (9)	0.0060 (9)	−0.0048 (9)
C15	0.0227 (12)	0.0151 (10)	0.0204 (11)	−0.0042 (9)	0.0023 (9)	0.0021 (9)
C16	0.0220 (12)	0.0291 (12)	0.0216 (11)	0.0012 (10)	−0.0047 (9)	0.0014 (10)

Geometric parameters (Å, º)

O1—C2	1.332 (2)	C6—C9	1.483 (3)
O1—C1	1.442 (2)	C7—C8	1.379 (3)
O2—C2	1.211 (2)	C7—H7A	0.9500
O3—C15	1.342 (2)	C8—H8A	0.9500
O3—C16	1.443 (2)	C9—C14	1.396 (3)
O4—C15	1.204 (2)	C9—C10	1.399 (3)
N1—C5	1.379 (3)	C10—C11	1.383 (3)
N1—H1NB	0.877 (5)	C10—H10A	0.9500
N1—H1NA	0.879 (5)	C11—C12	1.388 (3)
C1—H1C	0.9800	C11—H11A	0.9500
C1—H1B	0.9800	C12—C13	1.391 (3)
C1—H1A	0.9800	C12—C15	1.485 (3)
C2—C3	1.482 (3)	C13—C14	1.376 (3)
C3—C4	1.388 (3)	C13—H13A	0.9500
C3—C8	1.390 (3)	C14—H14A	0.9500
C4—C5	1.397 (3)	C16—H16A	0.9800
C4—H4A	0.9500	C16—H16B	0.9800
C5—C6	1.413 (3)	C16—H16C	0.9800
C6—C7	1.399 (3)
C2—O1—C1	116.20 (16)	C7—C8—H8A	120.6
C15—O3—C16	115.67 (16)	C3—C8—H8A	120.6
C5—N1—H1NB	113.4 (17)	C14—C9—C10	118.07 (19)
C5—N1—H1NA	117.6 (17)	C14—C9—C6	118.81 (18)
H1NB—N1—H1NA	120 (2)	C10—C9—C6	123.01 (19)
O1—C1—H1C	109.5	C11—C10—C9	120.68 (19)
O1—C1—H1B	109.5	C11—C10—H10A	119.7
H1C—C1—H1B	109.5	C9—C10—H10A	119.7
O1—C1—H1A	109.5	C10—C11—C12	120.51 (18)
H1C—C1—H1A	109.5	C10—C11—H11A	119.7
H1B—C1—H1A	109.5	C12—C11—H11A	119.7
O2—C2—O1	122.46 (19)	C11—C12—C13	119.20 (19)
O2—C2—C3	125.17 (19)	C11—C12—C15	119.80 (18)
O1—C2—C3	112.37 (17)	C13—C12—C15	121.00 (19)
C4—C3—C8	120.21 (18)	C14—C13—C12	120.3 (2)
C4—C3—C2	117.99 (18)	C14—C13—H13A	119.9
C8—C3—C2	121.80 (18)	C12—C13—H13A	119.9
C3—C4—C5	121.22 (19)	C13—C14—C9	121.25 (18)
C3—C4—H4A	119.4	C13—C14—H14A	119.4
C5—C4—H4A	119.4	C9—C14—H14A	119.4
N1—C5—C4	117.78 (19)	O4—C15—O3	123.07 (19)
N1—C5—C6	123.24 (18)	O4—C15—C12	125.2 (2)
C4—C5—C6	118.97 (18)	O3—C15—C12	111.68 (17)
C7—C6—C5	118.25 (18)	O3—C16—H16A	109.5
C7—C6—C9	118.09 (18)	O3—C16—H16B	109.5
C5—C6—C9	123.65 (18)	H16A—C16—H16B	109.5
C8—C7—C6	122.60 (19)	O3—C16—H16C	109.5
C8—C7—H7A	118.7	H16A—C16—H16C	109.5
C6—C7—H7A	118.7	H16B—C16—H16C	109.5
C7—C8—C3	118.75 (19)
C1—O1—C2—O2	2.4 (3)	C5—C6—C9—C14	−136.4 (2)
C1—O1—C2—C3	−177.63 (17)	C7—C6—C9—C10	−133.4 (2)
O2—C2—C3—C4	−0.5 (3)	C5—C6—C9—C10	47.5 (3)
O1—C2—C3—C4	179.46 (17)	C14—C9—C10—C11	−0.5 (3)
O2—C2—C3—C8	−179.8 (2)	C6—C9—C10—C11	175.68 (19)
O1—C2—C3—C8	0.2 (3)	C9—C10—C11—C12	0.1 (3)
C8—C3—C4—C5	1.0 (3)	C10—C11—C12—C13	0.0 (3)
C2—C3—C4—C5	−178.30 (18)	C10—C11—C12—C15	179.73 (18)
C3—C4—C5—N1	−179.38 (19)	C11—C12—C13—C14	0.3 (3)
C3—C4—C5—C6	−0.6 (3)	C15—C12—C13—C14	−179.44 (18)
N1—C5—C6—C7	178.43 (19)	C12—C13—C14—C9	−0.7 (3)
C4—C5—C6—C7	−0.2 (3)	C10—C9—C14—C13	0.8 (3)
N1—C5—C6—C9	−2.5 (3)	C6—C9—C14—C13	−175.55 (18)
C4—C5—C6—C9	178.85 (18)	C16—O3—C15—O4	1.7 (3)
C5—C6—C7—C8	0.8 (3)	C16—O3—C15—C12	−179.20 (16)
C9—C6—C7—C8	−178.35 (19)	C11—C12—C15—O4	−2.0 (3)
C6—C7—C8—C3	−0.5 (3)	C13—C12—C15—O4	177.7 (2)
C4—C3—C8—C7	−0.4 (3)	C11—C12—C15—O3	178.96 (18)
C2—C3—C8—C7	178.82 (19)	C13—C12—C15—O3	−1.3 (3)
C7—C6—C9—C14	42.7 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1NB···O2^i	0.88 (1)	2.54 (2)	3.304 (3)	146 (2)
N1—H1NA···O4^ii	0.88 (1)	2.33 (1)	3.147 (2)	155 (2)
C4—H4A···O2^i	0.95	2.44	3.301 (3)	150

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