Crystal structures of 4-chloro­pyridine-2-carbo­nitrile and 6-chloro­pyridine-2-carbo­nitrile exhibit different inter­molecular π-stacking, C—H⋯Nnitrile and C—H⋯Npyridine inter­actions

Montgomery, M.J.; O'Connor, T.J.; Tanski, J.M.

doi:10.1107/S2056989015011767

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 71| Part 7| July 2015| Pages 852-856

doi:10.1107/S2056989015011767

Open

access

Crystal structures of 4-chloropyridine-2-carbonitrile and 6-chloropyridine-2-carbonitrile exhibit different intermolecular π-stacking, C—H⋯N_nitrile and C—H⋯N_pyridine interactions

Matthew J. Montgomery,^a Thomas J. O'Connor ^a and Joseph M. Tanski ^a ^*

^aDepartment of Chemistry, Vassar College, Poughkeepsie, NY 12604, USA
^*Correspondence e-mail: jotanski@vassar.edu

Edited by C. Rizzoli, Universita degli Studi di Parma, Italy (Received 11 June 2015; accepted 18 June 2015; online 27 June 2015)

The two title compounds are isomers of C₆H₃ClN₂ containing a pyridine ring, a nitrile group, and a chloro substituent. The molecules of each compound pack together in the solid state with offset face-to-face π-stacking, and intermolecular C—H⋯N_nitrile and C—H⋯N_pyridine interactions. 4-Chloropyridine-2-carbonitrile, (I), exhibits pairwise centrosymmetric head-to-head C—H⋯N_nitrile and C—H⋯N_pyridine interactions, forming one-dimensional chains, which are π-stacked in an offset face-to-face fashion. The intermolecular packing of the isomeric 6-chloropyridine-2-carbonitrile, (II), which differs only in the position of the chloro substituent on the pyridine ring, exhibits head-to-tail C—H⋯N_nitrile and C—H⋯N_pyridine interactions, forming two-dimensional sheets which are π-stacked in an offset face-to-face fashion. In contrast to (I), the offset face-to-face π-stacking in (II) is formed between molecules with alternating orientations of the chloro and nitrile substituents.

Keywords: crystal structure; chlorocyanopyridine; π-stacking; C—H⋯N interactions.

CCDC references: 1407613; 1407612

1. Chemical context

Chloropyridinecarbonitriles are members of a class of compounds containing the ubiquitous six-membered nitrogen-containing heterocycle pyridine. The pyridine heterocycle features prominently in many valuable synthetic compounds (Bull et al., 2012 ). While several of the ten possible isomers of chloropyridinecarbonitrile are commercially available, none of their crystal structures have been reported in the literature, although the structure of 2-chloropyridine-4-carbonitrile has been deposited in the Cambridge Structural Database (Version 5.31, June 2015 with updates; Groom & Allen, 2014 ) as a private communication (refcode LOBVIJ). The title compounds represent two isomers of chloropyridine-2-carbonitrile, namely 4-chloropyridine-2-carbonitrile, (I), and 6-chloropyridine-2-carbonitrile, (II). In both cases, the intramolecular packing exhibits weak intermolecular C—H⋯N interactions, which are well documented (Desiraju & Steiner, 1999 ), as well as aromatic π-stacking interactions (Hunter & Saunders, 1990 ; Lueckheide et al., 2013 ).

4-Chloropyridine-2-carbonitrile, (I), may be synthesized by the cyanation of 4-chloropyridine N-oxide with trimethylsilanecarbonitrile (TMSCN) (Sakamoto et al., 1985 ). More recently, it has been shown that (I) can be prepared in a one-step process from 4-nitropyridine N-oxide with ethyl chloroformate and TMSCN (Veerareddy et al., 2011 ). (I) has found use as a building block for a family of chiral catalysts (Busto et al., 2005 ).

6-Chloropyridine-2-carbonitrile, (II), may be synthesized by the vapor-phase chlorination of 2-cyanopyridine (Ruetman & Taplin, 1971 ), or by the cyanation of 2-chloropyridine N-oxide hydrochloride with sodium cyanide (Tsukamoto et al., 2009 ). This compound has found applications in the preparation of biologically active or pharmaceutical compounds, such as heteroaromatic carboxylic acids (Kiener et al., 1996 ) and 2-arylamino-substituted pyridinyl nitriles (Guo et al., 2013 ).

2. Structural commentary

4-Chloropyridine-2-carbonitrile, (I) (Fig. 1), and 6-chloropyridine-2-carbonitrile, (II) (Fig. 2), exhibit similar metrical parameters. The nitrile bond length C1—N2 of 1.156 (3) Å in (I) and 1.138 (2) Å in (II) are similar to those seen in the related structure 2-chloropyridine-4-carbonitrile, with the nitrile C≡N distance is 1.141 Å (CSD refcode LOBVIJ). The nitrile bond lengths in 2- and 3-cyanopyridine [1.145 (2) and 1.150 (1) Å, respectively; Kubiak et al., 2002 ] and 4-cyanopyridine [1.137 (8) Å; Laing et al., 1971 ] are also similar to those found in the title compounds. The aromatic chlorine bond lengths, viz. C4—Cl and C6—Cl of 1.740 (3) Å in (I) and 1.740 (1) Å in (II), are similar to those seen in the related structures 2-chloropyridine-4-carbonitrile (1.732 Å; CSD refcode LOBVIJ), 2- and 3-chloropyridine hydrochloride (1.710 and 1.727 Å, respectively; Freytag & Jones, 2001 ), and 4-chloropyridine hydrochloride (1.730 Å; Freytag et al., 1999 ).

Figure 1
A view of 4-chloropyridine-2-carbonitrile, (I)

, with the atom-numbering scheme. Displacement ellipsoids are shown at the 50% probability level.

Figure 2
A view of 6-chloropyridine-2-carbonitrile, (II)

, with the atom-numbering scheme. Displacement ellipsoids are shown at the 50% probability level.

Both (I) and (II) are almost planar, with r.m.s. deviations from the mean planes of all non-H atoms of 0.0077 and 0.0161 Å, respectively. As may be expected, the heterocyclic rings are slightly wedge shaped as the pyridine C—N bond are shorter than the C—C bonds in each aromatic ring. In (I), the ring C2—N1 and C6—N1 bond lengths of 1.361 (3) and 1.350 (3) Å are similar to those found in (II) of 1.349 (1) and 1.322 (1) Å. The average ring C—C bond lengths are 1.403 (2) Å in (I) and 1.391 (5) Å in (II). The lengths are comparable to those found in the parent compound, pyridine, with C—N of 1.34 Å and C—C of 1.38 Å (Mootz & Wussow, 1981 ), and in the related structure 2-chloropyridine-4-carbonitrile, with C—N bond lengths of 1.328 and 1.340 Å, and an average C—C bond length of 1.377 (7) Å (CSD refcode LOBVIJ).

3. Supramolecular features

The molecules of each of the title compounds pack together in the solid state with π-stacking, and intermolecular C—H⋯N_nitrile and C—H⋯N_pyridine interactions, however, the packing motifs are unique, and also different than those found in the related structure 2-chloropyridine-4-carbonitrile (CSD refcode LOBVIJ). For a discussion of weak C—H⋯X interactions, see Desiraju & Steiner (1999).

The molecules of (I) pack together in the solid state via alternating centrosymmetric head-to-head intermolecular C—H⋯N_nitrile and C—H⋯N_pyridine interactions to form a one-dimensional zigzag chain (Fig. 3 and Table 1). The chains further pack together through offset face-to-face π-stacking (Fig. 4). This π-stacking is characterized by a centroid-to-centroid distance of 3.813 (5) Å, a plane-to-centroid distance of 3.454 (4) Å, and a ring offset or ring-slippage distance of 1.615 (3) Å (Hunter & Saunders, 1990; Lueckheide et al., 2013). The π-stacking in (I) is similar to that found in the related unpublished structure 2-chloropyridine-4-carbonitrile (CSD refcode LOBVIJ).

Table 1
Hydrogen-bond geometry (Å, °) for (I)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯N2ⁱ	0.95	2.64	3.462 (5)	146
C6—H6A⋯N1ⁱⁱ	0.95	2.75	3.493 (5)	136
Symmetry codes: (i) -x-1, -y+1, -z; (ii) -x, -y+1, -z+1.

Figure 3
A view of the intermolecular C—H⋯N_nitrile and C—H⋯N_pyridine contacts (dashed lines) in 4-chloropyridine-2-carbonitrile, (I)

, that form a one-dimensional chain. [Symmetry codes: (i) −x − 1, −y + 1, −z; (ii) −x, −y + 1, −z + 1.]

Figure 4
A view of the offset face-to-face π-stacking in 4-chloropyridine-2-carbonitrile, (I)

, with the thick dashed line indicating a centroid-to-centroid interaction. [Symmetry code: (i) x + 1, y, z.]

In contrast to (I), the molecules of (II) pack together via head-to-tail C—H⋯N_nitrile and C—H⋯N_pyridine interactions to form two-dimensional sheets that are parallel to the (001) plane (Fig. 5 and Table 2). As in (I), the parallel planes of the molecules engage in offset face-to-face π-stacking between the two-dimensional sheets, which is characterized by a ring centroid-to-centroid distance of 3.7204 (7) Å, a centroid-to-plane distance of 3.41 (1) Å, and a ring-offset slippage of 1.48 (2) Å (Fig. 6). However, in constrast to (I), the π-stacking in (II) is formed between molecules with alternating orientations of the chloro and nitrile substituents with a plane-to-plane angle of 0.23 (5)°. For a more thorough description of π-stacking, see Hunter & Saunders (1990) and Lueckheide et al. (2013).

Table 2
Hydrogen-bond geometry (Å, °) for (II)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C4—H4A⋯N1ⁱ	0.95	2.49	3.4099 (15)	164
C5—H5A⋯N2ⁱⁱ	0.95	2.70	3.5651 (17)	152
Symmetry codes: (i) x-1, y, z; (ii) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]$ .

Figure 5
A view of the intermolecular C—H⋯N_nitrile and C—H⋯N_pyridine contacts (dashed lines) in 6-chloropyridine-2-carbonitrile, (I)

, that form a two-dimensional sheet. [Symmetry codes: (i) x − 1, y, z; (ii) −x + $[{3\over 2}]$ , y − $[{1\over 2}]$ , −z + $[{3\over 2}]$ .]

Figure 6
A view of the alternating offset face-to-face π-stacking in 6-chloropyridine-2-carbonitrile, (II)

, with the thick dashed line indicating a centroid-to-centroid interaction. [Symmetry code: (i) x + $[{1\over 2}]$ , −y + $[{1\over 2}]$ , z + $[{1\over 2}]$ .]

Notably, there are no significant Cl⋯Cl contacts in (I) or (II), in contrast to 2-chloropyridine-4-carbonitrile (CSD refcode LOBVIJ), which exhibits a Cl⋯Cl contact distance of 3.371 Å that is shorter than the sum of the van der Waals radius of chlorine (3.5 Å; Bondi, 1964 ). For more information on halide–halide contacts, see Pedireddi et al. (1994 ) and Jelsch et al. (2015 ).

4. Synthesis and crystallization

4-Chloropyridine-2-carbonitrile (97%) and 6-chloropyridine-2-carbonitrile (96%) were purchased from Aldrich Chemical Company, USA. 4-Chloropyridine-2-carbonitrile was recrystallized from 95% ethanol.

5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3. H atoms on C atoms were included in calculated positions and refined using a riding model, with C—H = 0.95 Å and U_iso(H) = 1.2U_eq(C) of the aryl C atoms.

Table 3
Experimental details

	(I)	(II)
Crystal data
Chemical formula	C₆H₃ClN₂	C₆H₃ClN₂
M_r	138.55	138.55
Crystal system, space group	Monoclinic, P2₁/n	Monoclinic, P2₁/n
Temperature (K)	125	125
a, b, c (Å)	3.813 (5), 14.047 (19), 11.356 (15)	6.1739 (15), 15.238 (4), 7.0123 (18)
β (°)	96.806 (19)	112.492 (4)
V (Å³)	604.0 (14)	609.5 (3)
Z	4	4
Radiation type	Mo Kα	Mo Kα
μ (mm⁻¹)	0.52	0.52
Crystal size (mm)	0.25 × 0.10 × 0.04	0.20 × 0.15 × 0.03

Data collection
Diffractometer	Bruker APEXII CCD	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2013 )	Multi-scan (SADABS; Bruker, 2013)
T_min, T_max	0.67, 0.98	0.82, 0.98
No. of measured, independent and observed [I > 2σ(I)] reflections	12191, 1852, 1498	15460, 1868, 1657
R_int	0.063	0.031
(sin θ/λ)_max (Å⁻¹)	0.715	0.717

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.135, 1.12	0.028, 0.082, 1.09
No. of reflections	1852	1868
No. of parameters	82	82
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.53, −0.37	0.48, −0.19
Computer programs: APEX2 and SAINT (Bruker, 2013), SHELXS2014 and SHELXTL2014 (Sheldrick, 2008 ), SHELXL2014 (Sheldrick, 2015 ), OLEX2 (Dolomanov et al., 2009 ) and Mercury (Macrae et al., 2008 ).

Supporting information

CCDC references: 1407613; 1407612

Crystal structure: contains datablocks global, I, II. DOI: 10.1107/S2056989015011767/rz5161sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S2056989015011767/rz5161Isup2.hkl

Structure factors: contains datablock II. DOI: 10.1107/S2056989015011767/rz5161IIsup3.hkl

Supporting information file. DOI: 10.1107/S2056989015011767/rz5161Isup4.cml

Supporting information file. DOI: 10.1107/S2056989015011767/rz5161IIsup5.cml

checkCIF report

Chemical context top

Chloropyridinecarbonitriles are members of a class of compounds containing the ubiquitous six-membered nitrogen-containing heterocycle pyridine. The pyridine heterocycle features prominently in many valuable synthetic compounds (Bull et al., 2012). While several of the ten possible isomers of chloropyridinecarbonitrile are commercially available, none of their crystal structures have been reported in the literature, although the structure of 2-chloropyridine-4-carbonitrile has been deposited in the Cambridge Structural Database (Version 5.31, June 2015 with updates; Groom & Allen, 2014) as a private communication (refcode LOBVIJ). The title compounds represent two isomers of chloropyridine-2-carbonitrile, namely 4-chloropyridine-2-carbonitrile, (I), and 6-chloropyridine-2-carbonitrile, (II). In both cases, the intramolecular packing exhibits weak intermolecular C—H···N interactions, which are well documented (Desiraju & Steiner, 1999), as well as aromatic π-stacking interactions (Hunter & Saunders, 1990; Lueckheide et al., 2013).

4-Chloropyridine-2-carbonitrile, (I), may be synthesized by the cyanation of 4-chloropyridine N-oxide with trimethylsilanecarbonitrile (TMSCN) (Sakamoto et al., 1985). More recently, it has been shown that (I) can be prepared in a one-step process from 4-nitropyridine N-oxide with ethyl chloroformate and TMSCN (Veerareddy et al., 2011). (I) has found use as a building block for a family of chiral catalysts (Busto et al., 2005) and in the synthesis of 2-arylamino-substituted pyridinyl nitriles (Guo et al., 2013).

6-Chloropyridine-2-carbonitrile, (II), may be synthesized by the vapor-phase chlorination of 2-cyanopyridine (Ruetman & Taplin, 1971), or by the cyanation of 2-chloropyridine N-oxide hydrochloride with sodium cyanide (Tsukamoto et al., 2009). This compound has found applications in the preparation of biologically active or pharmaceutical compounds, such as heteroaromatic carboxylic acids (Kiener et al., 1996) and 2-arylamino substituted pyridinyl nitriles (Guo et al., 2013).

Structural commentary top

4-Chloropyridine-2-carbonitrile, (I) (Fig. 1), and 6-chloropyridine-2-carbonitrile, (II) (Fig. 2), exhibit similar metrical parameters. The nitrile bond length C1—N2 of 1.156 (3) Å in (I) and 1.138 (2) Å in (II) are similar to those seen in the related structure 2-chloropyridine-4-carbonitrile, with the nitrile C≡N distance is 1.141 Å (CSD refcode LOBVIJ). The nitrile bond lengths in 2- and 3-cyanopyridine [1.145 (2) and 1.150 (1) Å, respectively; Kubiak et al., 2002] and 4-cyanopyridine [1.137 (8) Å; Laing et al., 1971] are also similar to those found in the title compounds. The aromatic chloride bond lengths, viz. C4—Cl and C6—Cl of 1.740 (3) Å in (I) and 1.740 (1) Å in (II), are similar to those seen in the related structures 2-chloropyridine-4-carbonitrile (1.732 Å; CSD refcode LOBVIJ), 2- and 3-chloropyridine hydrochloride (1.710 and 1.727 Å, respectively; Freytag & Jones, 2001), and 4-chloropyridine hydrochloride (1.730 Å; Freytag et al., 1999).

Both (I) and (II) are planar, with r.m.s. deviations from the mean planes of all non-H atoms of 0.0077 and 0.0161 Å, respectively. As may be expected, the heterocyclic rings are slightly wedge shaped as the pyridine C—N bond are shorter than the C—C bonds in each aromatic ring. In (I), the ring C2—N1 and C6—N1 bond lengths of 1.361 (3) and 1.350 (3) Å are similar to those found in (II) of 1.349 (1) and 1.322 (1) Å. The average ring C—C bond lengths are 1.403 (2) Å in (I) and 1.391 (5) Å in (II). The lengths are comparable to those found in the parent compound, pyridine, with C—N of 1.34 Å and C—C of 1.38 Å (Mootz & Wussow, 1981), and in the related structure 2-chloropyridine-4-carbonitrile, with C—N bond lengths of 1.328 and 1.340 Å, and an average C—C bond length of 1.377 (7) Å (CSD refcode LOBVIJ).

Supramolecular features top

The molecules of each of the title compound pack together in the solid state with π-stacking, and intermolecular C—H···N_nitrile and C—H···N_pyridine interactions, however, the packing motifs are unique, and also different than those found in the related structure 2-chloropyridine-4-carbonitrile (CSD refcode LOBVIJ). For a discussion of weak C—H···X interactions, see Desiraju & Steiner (1999).

The molecules of (I) pack together in the solid state via alternating centrosymmetric head-to-head intermolecular C—H···N_nitrile and C—H···N_pyridine interactions to form a one-dimensional zigzag chain (Fig. 3 and Table 1). The chains further pack together through offset face-to-face π-stacking (Fig. 4). This π-stacking is characterized by a centroid-to-centroid distance of 3.813 (5) Å, a plane-to-centroid distance of 3.454 (4) Å, and a ring offset or ring-slippage distance of 1.615 (3) Å (Hunter & Saunders, 1990; Lueckheide et al., 2013). The π-stacking in (I) is similar to that found in the related unpublished structure 2-chloropyridine-4-carbonitrile (CSD refcode LOBVIJ).

In contrast to (I), the molecules of (II) pack together via head-to-tail C—H···N_nitrile and C—H···N_pyridine interactions to form two-dimensional sheets that are parallel to the (001) plane (Fig. 5 and Table 2). As in (I), the parallel planes of the molecules engage in offset face-to-face π-stacking between the two-dimensional sheets, which is characterized by a ring centroid-to-centroid distance of 3.7204 (7) Å, a centroid-to-plane distance of 3.41 (1) Å, and a ring-offset slippage of 1.48 (2) Å (Fig. 6). However, in constrast to (I), the π-stacking in (II) is formed between molecules with alternating orientations of the chloro and nitrile substituents with a plane-to-plane angle of 0.23 (5)°. For a more thorough description of π-stacking, see Hunter & Saunders (1990) and Lueckheide et al. (2013).

Notably, there are no significant Cl···Cl contacts in (I) or (II), in contrast to 2-chloropyridine-4-carbonitrile (CSD refcode LOBVIJ), which exhibits a Cl···Cl contact distance of 3.371 Å that is shorter than the sum of the van der Waals radius of chlorine (3.5 Å; Bondi, 1964). For more information on halide–halide contacts, see Pedireddi et al. (1994) and Jelsch et al. (2015).

Synthesis and crystallization top

4-Chloropyridine-2-carbonitrile (97%) and 6-chloropyridine-2-carbonitrile (96%) were purchased from Aldrich Chemical Company, USA. 4-Chloropyridine-2-carbonitrile was recrystallized from 95% ethanol.

Refinement top

Structure description top

Chloropyridinecarbonitriles are members of a class of compounds containing the ubiquitous six-membered nitrogen-containing heterocycle pyridine. The pyridine heterocycle features prominently in many valuable synthetic compounds (Bull et al., 2012). While several of the ten possible isomers of chloropyridinecarbonitrile are commercially available, none of their crystal structures have been reported in the literature, although the structure of 2-chloropyridine-4-carbonitrile has been deposited in the Cambridge Structural Database (Version 5.31, June 2015 with updates; Groom & Allen, 2014) as a private communication (refcode LOBVIJ). The title compounds represent two isomers of chloropyridine-2-carbonitrile, namely 4-chloropyridine-2-carbonitrile, (I), and 6-chloropyridine-2-carbonitrile, (II). In both cases, the intramolecular packing exhibits weak intermolecular C—H···N interactions, which are well documented (Desiraju & Steiner, 1999), as well as aromatic π-stacking interactions (Hunter & Saunders, 1990; Lueckheide et al., 2013).

4-Chloropyridine-2-carbonitrile, (I), may be synthesized by the cyanation of 4-chloropyridine N-oxide with trimethylsilanecarbonitrile (TMSCN) (Sakamoto et al., 1985). More recently, it has been shown that (I) can be prepared in a one-step process from 4-nitropyridine N-oxide with ethyl chloroformate and TMSCN (Veerareddy et al., 2011). (I) has found use as a building block for a family of chiral catalysts (Busto et al., 2005) and in the synthesis of 2-arylamino-substituted pyridinyl nitriles (Guo et al., 2013).

6-Chloropyridine-2-carbonitrile, (II), may be synthesized by the vapor-phase chlorination of 2-cyanopyridine (Ruetman & Taplin, 1971), or by the cyanation of 2-chloropyridine N-oxide hydrochloride with sodium cyanide (Tsukamoto et al., 2009). This compound has found applications in the preparation of biologically active or pharmaceutical compounds, such as heteroaromatic carboxylic acids (Kiener et al., 1996) and 2-arylamino substituted pyridinyl nitriles (Guo et al., 2013).

4-Chloropyridine-2-carbonitrile, (I) (Fig. 1), and 6-chloropyridine-2-carbonitrile, (II) (Fig. 2), exhibit similar metrical parameters. The nitrile bond length C1—N2 of 1.156 (3) Å in (I) and 1.138 (2) Å in (II) are similar to those seen in the related structure 2-chloropyridine-4-carbonitrile, with the nitrile C≡N distance is 1.141 Å (CSD refcode LOBVIJ). The nitrile bond lengths in 2- and 3-cyanopyridine [1.145 (2) and 1.150 (1) Å, respectively; Kubiak et al., 2002] and 4-cyanopyridine [1.137 (8) Å; Laing et al., 1971] are also similar to those found in the title compounds. The aromatic chloride bond lengths, viz. C4—Cl and C6—Cl of 1.740 (3) Å in (I) and 1.740 (1) Å in (II), are similar to those seen in the related structures 2-chloropyridine-4-carbonitrile (1.732 Å; CSD refcode LOBVIJ), 2- and 3-chloropyridine hydrochloride (1.710 and 1.727 Å, respectively; Freytag & Jones, 2001), and 4-chloropyridine hydrochloride (1.730 Å; Freytag et al., 1999).

Synthesis and crystallization top

4-Chloropyridine-2-carbonitrile (97%) and 6-chloropyridine-2-carbonitrile (96%) were purchased from Aldrich Chemical Company, USA. 4-Chloropyridine-2-carbonitrile was recrystallized from 95% ethanol.

Refinement details top

Computing details top

For both compounds, data collection: APEX2 (Bruker, 2013); cell refinement: APEX2 (Bruker, 2013); data reduction: SAINT (Bruker, 2013); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL2014 (Sheldrick, 2008); software used to prepare material for publication: SHELXTL2014 (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008).

Figures top

	Fig. 1. A view of 4-chloropyridine-2-carbonitrile, (I), with the atom-numbering scheme. Displacement ellipsoids are shown at the 50% probability level.
	Fig. 2. A view of 6-chloropyridine-2-carbonitrile, (II), with the atom-numbering scheme. Displacement ellipsoids are shown at the 50% probability level.
	Fig. 3. A view of the intermolecular C—H···N_nitrile and C—H···N_pyridine contacts (dashed lines) in 4-chloropyridine-2-carbonitrile, (I), that form a one-dimensional chain. [Symmetry codes: (i) -x-1, -y+1, -z; (ii) -x, -y+1, -z+1.]
	Fig. 4. A view of the offset face-to-face π-stacking in 4-chloropyridine-2-carbonitrile, (I), with the thick dashed line indicating a centroid-to-centroid interaction. [Symmetry code: (i) x+1, y, z.]
	Fig. 5. A view of the intermolecular C—H···N_nitrile and C—H···N_pyridine contacts (dashed lines) in 6-chloropyridine-2-carbonitrile, (I), that form a two-dimensional sheet. [Symmetry codes: (i) x-1, y, z; (ii) -x+3/2, y-1/2, -z+3/2.]
	Fig. 6. A view of the alternating offset face-to-face π-stacking in 6-chloropyridine-2-carbonitrile, (II), with the thick dashed line indicating a centroid-to-centroid interaction. [Symmetry code: (i) x+1/2, -y+1/2, z+1/2.]

(I) 4-Chloropyridine-2-carbonitrile top

Crystal data top

C₆H₃ClN₂	F(000) = 280
M_r = 138.55	D_x = 1.524 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 3.813 (5) Å	Cell parameters from 3637 reflections
b = 14.047 (19) Å	θ = 2.9–30.3°
c = 11.356 (15) Å	µ = 0.52 mm⁻¹
β = 96.806 (19)°	T = 125 K
V = 604.0 (14) Å³	Plate, colourless
Z = 4	0.25 × 0.10 × 0.04 mm

Data collection top

Bruker APEXII CCD diffractometer	1852 independent reflections
Radiation source: fine-focus sealed tube	1498 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.063
Detector resolution: 8.3333 pixels mm^-1	θ_max = 30.6°, θ_min = 2.3°
φ and ω scans	h = −5→5
Absorption correction: multi-scan (SADABS; Bruker, 2013)	k = −20→19
T_min = 0.67, T_max = 0.98	l = −16→16
12191 measured reflections

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.050	H-atom parameters constrained
wR(F²) = 0.135	w = 1/[σ²(F_o²) + (0.0646P)² + 0.4268P] where P = (F_o² + 2F_c²)/3
S = 1.12	(Δ/σ)_max < 0.001
1852 reflections	Δρ_max = 0.53 e Å⁻³
82 parameters	Δρ_min = −0.37 e Å⁻³

Crystal data top

C₆H₃ClN₂	V = 604.0 (14) Å³
M_r = 138.55	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 3.813 (5) Å	µ = 0.52 mm⁻¹
b = 14.047 (19) Å	T = 125 K
c = 11.356 (15) Å	0.25 × 0.10 × 0.04 mm
β = 96.806 (19)°

Data collection top

Bruker APEXII CCD diffractometer	1852 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2013)	1498 reflections with I > 2σ(I)
T_min = 0.67, T_max = 0.98	R_int = 0.063
12191 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.135	H-atom parameters constrained
S = 1.12	Δρ_max = 0.53 e Å⁻³
1852 reflections	Δρ_min = −0.37 e Å⁻³
82 parameters

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cl	0.27576 (14)	0.79489 (4)	0.15624 (5)	0.02207 (17)
N1	0.0055 (5)	0.52050 (12)	0.33977 (16)	0.0197 (4)
N2	−0.4067 (5)	0.39592 (13)	0.09730 (18)	0.0253 (4)
C1	−0.2642 (5)	0.45592 (15)	0.15388 (19)	0.0204 (4)
C2	−0.0811 (5)	0.53460 (14)	0.22134 (18)	0.0173 (4)
C3	−0.0084 (5)	0.61731 (14)	0.15971 (18)	0.0177 (4)
H3A	−0.0758	0.6235	0.0768	0.021*
C4	0.1688 (5)	0.69050 (13)	0.22646 (18)	0.0163 (4)
C5	0.2634 (5)	0.67930 (15)	0.34888 (18)	0.0192 (4)
H5A	0.383	0.7283	0.3953	0.023*
C6	0.1748 (6)	0.59298 (15)	0.40037 (19)	0.0207 (4)
H6A	0.2382	0.5851	0.4832	0.025*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl	0.0217 (3)	0.0212 (3)	0.0227 (3)	−0.00411 (18)	0.00040 (18)	0.00357 (18)
N1	0.0200 (8)	0.0197 (8)	0.0191 (9)	0.0004 (6)	0.0016 (7)	0.0014 (7)
N2	0.0261 (9)	0.0245 (9)	0.0247 (10)	−0.0046 (7)	0.0003 (8)	−0.0011 (7)
C1	0.0176 (9)	0.0218 (9)	0.0216 (10)	0.0002 (7)	0.0019 (8)	0.0027 (8)
C2	0.0141 (8)	0.0180 (9)	0.0199 (10)	0.0012 (7)	0.0021 (7)	−0.0016 (7)
C3	0.0161 (9)	0.0217 (9)	0.0153 (9)	−0.0004 (7)	0.0020 (7)	−0.0001 (7)
C4	0.0144 (8)	0.0169 (8)	0.0180 (9)	0.0012 (7)	0.0032 (7)	0.0018 (7)
C5	0.0185 (9)	0.0201 (9)	0.0185 (10)	0.0003 (7)	0.0002 (8)	−0.0024 (7)
C6	0.0236 (10)	0.0230 (10)	0.0152 (9)	0.0012 (8)	0.0020 (8)	−0.0004 (7)

Geometric parameters (Å, º) top

Cl—C4	1.740 (3)	C3—C4	1.402 (3)
N1—C6	1.350 (3)	C3—H3A	0.95
N1—C2	1.361 (3)	C4—C5	1.403 (3)
N2—C1	1.156 (3)	C5—C6	1.405 (3)
C1—C2	1.473 (3)	C5—H5A	0.95
C2—C3	1.401 (3)	C6—H6A	0.95

C6—N1—C2	116.07 (19)	C3—C4—Cl	119.61 (18)
N2—C1—C2	177.6 (2)	C5—C4—Cl	120.11 (16)
N1—C2—C3	125.12 (19)	C4—C5—C6	117.58 (19)
N1—C2—C1	116.70 (19)	C4—C5—H5A	121.2
C3—C2—C1	118.2 (2)	C6—C5—H5A	121.2
C2—C3—C4	116.7 (2)	N1—C6—C5	124.3 (2)
C2—C3—H3A	121.7	N1—C6—H6A	117.9
C4—C3—H3A	121.7	C5—C6—H6A	117.9
C3—C4—C5	120.27 (19)

C6—N1—C2—C3	−0.1 (3)	C2—C3—C4—Cl	178.93 (15)
C6—N1—C2—C1	179.66 (19)	C3—C4—C5—C6	0.1 (3)
N1—C2—C3—C4	0.3 (3)	Cl—C4—C5—C6	−179.07 (16)
C1—C2—C3—C4	−179.48 (18)	C2—N1—C6—C5	−0.1 (3)
C2—C3—C4—C5	−0.3 (3)	C4—C5—C6—N1	0.1 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···N2ⁱ	0.95	2.64	3.462 (5)	146
C6—H6A···N1ⁱⁱ	0.95	2.75	3.493 (5)	136

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

(II) 6-Chloropyridine-2-carbonitrile top

Crystal data top

C₆H₃ClN₂	F(000) = 280
M_r = 138.55	D_x = 1.510 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
a = 6.1739 (15) Å	Cell parameters from 9960 reflections
b = 15.238 (4) Å	θ = 2.7–30.5°
c = 7.0123 (18) Å	µ = 0.52 mm⁻¹
β = 112.492 (4)°	T = 125 K
V = 609.5 (3) Å³	Plate, colourless
Z = 4	0.20 × 0.15 × 0.03 mm

Data collection top

Bruker APEXII CCD diffractometer	1868 independent reflections
Radiation source: fine-focus sealed tube	1657 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
Detector resolution: 8.3333 pixels mm^-1	θ_max = 30.6°, θ_min = 2.7°
φ and ω scans	h = −8→8
Absorption correction: multi-scan (SADABS; Bruker, 2013)	k = −21→21
T_min = 0.82, T_max = 0.98	l = −10→9
15460 measured reflections

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.028	H-atom parameters constrained
wR(F²) = 0.082	w = 1/[σ²(F_o²) + (0.0424P)² + 0.1697P] where P = (F_o² + 2F_c²)/3
S = 1.09	(Δ/σ)_max = 0.001
1868 reflections	Δρ_max = 0.48 e Å⁻³
82 parameters	Δρ_min = −0.19 e Å⁻³

Crystal data top

C₆H₃ClN₂	V = 609.5 (3) Å³
M_r = 138.55	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 6.1739 (15) Å	µ = 0.52 mm⁻¹
b = 15.238 (4) Å	T = 125 K
c = 7.0123 (18) Å	0.20 × 0.15 × 0.03 mm
β = 112.492 (4)°

Data collection top

Bruker APEXII CCD diffractometer	1868 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2013)	1657 reflections with I > 2σ(I)
T_min = 0.82, T_max = 0.98	R_int = 0.031
15460 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.028	0 restraints
wR(F²) = 0.082	H-atom parameters constrained
S = 1.09	Δρ_max = 0.48 e Å⁻³
1868 reflections	Δρ_min = −0.19 e Å⁻³
82 parameters

Special details top

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Cl	1.01050 (5)	0.09596 (2)	0.82065 (4)	0.02803 (10)
N1	0.98012 (14)	0.26545 (6)	0.82258 (13)	0.01720 (17)
N2	1.10287 (19)	0.47889 (7)	0.79286 (18)	0.0351 (2)
C1	1.00059 (18)	0.41966 (8)	0.81170 (17)	0.0232 (2)
C2	0.87412 (16)	0.34169 (7)	0.83298 (15)	0.01728 (19)
C3	0.66223 (17)	0.34787 (7)	0.85770 (15)	0.0198 (2)
H3A	0.5958	0.4032	0.8664	0.024*
C4	0.55044 (17)	0.26976 (8)	0.86928 (16)	0.0210 (2)
H4A	0.4041	0.271	0.8846	0.025*
C5	0.65405 (17)	0.19009 (7)	0.85828 (15)	0.0205 (2)
H5A	0.5818	0.1359	0.8659	0.025*
C6	0.86897 (17)	0.19295 (7)	0.83550 (15)	0.01759 (19)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl	0.03124 (16)	0.02096 (15)	0.03084 (16)	0.00422 (9)	0.01070 (11)	−0.00400 (9)
N1	0.0135 (3)	0.0212 (4)	0.0168 (4)	−0.0004 (3)	0.0058 (3)	−0.0014 (3)
N2	0.0343 (5)	0.0294 (5)	0.0430 (6)	−0.0068 (4)	0.0164 (5)	0.0013 (4)
C1	0.0207 (5)	0.0237 (5)	0.0250 (5)	0.0006 (4)	0.0085 (4)	−0.0006 (4)
C2	0.0148 (4)	0.0199 (4)	0.0167 (4)	−0.0007 (3)	0.0055 (3)	−0.0001 (3)
C3	0.0154 (4)	0.0238 (5)	0.0204 (4)	0.0035 (3)	0.0071 (3)	0.0010 (4)
C4	0.0135 (4)	0.0317 (5)	0.0187 (4)	−0.0012 (4)	0.0072 (3)	0.0010 (4)
C5	0.0182 (4)	0.0246 (5)	0.0186 (4)	−0.0051 (3)	0.0068 (3)	0.0004 (4)
C6	0.0175 (4)	0.0193 (4)	0.0151 (4)	0.0004 (3)	0.0052 (3)	−0.0012 (3)

Geometric parameters (Å, º) top

Cl—C6	1.7402 (11)	C3—C4	1.3938 (15)
N1—C6	1.3218 (13)	C3—H3A	0.95
N1—C2	1.3490 (13)	C4—C5	1.3881 (16)
N2—C1	1.1378 (16)	C4—H4A	0.95
C1—C2	1.4604 (15)	C5—C6	1.3965 (14)
C2—C3	1.3870 (14)	C5—H5A	0.95

C6—N1—C2	116.15 (9)	C5—C4—H4A	120.2
N2—C1—C2	177.99 (12)	C3—C4—H4A	120.2
N1—C2—C3	124.44 (9)	C4—C5—C6	117.21 (9)
N1—C2—C1	113.94 (9)	C4—C5—H5A	121.4
C3—C2—C1	121.62 (9)	C6—C5—H5A	121.4
C2—C3—C4	117.46 (9)	N1—C6—C5	125.09 (9)
C2—C3—H3A	121.3	N1—C6—Cl	114.83 (8)
C4—C3—H3A	121.3	C5—C6—Cl	120.07 (8)
C5—C4—C3	119.65 (9)

C6—N1—C2—C3	0.62 (14)	C3—C4—C5—C6	−0.07 (15)
C6—N1—C2—C1	−178.24 (8)	C2—N1—C6—C5	0.12 (15)
N1—C2—C3—C4	−1.03 (15)	C2—N1—C6—Cl	179.80 (7)
C1—C2—C3—C4	177.74 (9)	C4—C5—C6—N1	−0.38 (15)
C2—C3—C4—C5	0.71 (15)	C4—C5—C6—Cl	179.96 (7)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4A···N1ⁱ	0.95	2.49	3.4099 (15)	164
C5—H5A···N2ⁱⁱ	0.95	2.70	3.5651 (17)	152

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

Hydrogen-bond geometry (Å, º) for (I) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···N2ⁱ	0.95	2.64	3.462 (5)	145.5
C6—H6A···N1ⁱⁱ	0.95	2.75	3.493 (5)	136.0

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

Hydrogen-bond geometry (Å, º) for (II) top

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4A···N1ⁱ	0.95	2.49	3.4099 (15)	164.4
C5—H5A···N2ⁱⁱ	0.95	2.70	3.5651 (17)	151.7

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

Experimental details

	(I)	(II)
Crystal data
Chemical formula	C₆H₃ClN₂	C₆H₃ClN₂
M_r	138.55	138.55
Crystal system, space group	Monoclinic, P2₁/n	Monoclinic, P2₁/n
Temperature (K)	125	125
a, b, c (Å)	3.813 (5), 14.047 (19), 11.356 (15)	6.1739 (15), 15.238 (4), 7.0123 (18)
β (°)	96.806 (19)	112.492 (4)
V (Å³)	604.0 (14)	609.5 (3)
Z	4	4
Radiation type	Mo Kα	Mo Kα
µ (mm⁻¹)	0.52	0.52
Crystal size (mm)	0.25 × 0.10 × 0.04	0.20 × 0.15 × 0.03

Data collection
Diffractometer	Bruker APEXII CCD	Bruker APEXII CCD
Absorption correction	Multi-scan (SADABS; Bruker, 2013)	Multi-scan (SADABS; Bruker, 2013)
T_min, T_max	0.67, 0.98	0.82, 0.98
No. of measured, independent and observed [I > 2σ(I)] reflections	12191, 1852, 1498	15460, 1868, 1657
R_int	0.063	0.031
(sin θ/λ)_max (Å⁻¹)	0.715	0.717

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.135, 1.12	0.028, 0.082, 1.09
No. of reflections	1852	1868
No. of parameters	82	82
H-atom treatment	H-atom parameters constrained	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.53, −0.37	0.48, −0.19

Computer programs: APEX2 (Bruker, 2013), SAINT (Bruker, 2013), SHELXS2014 (Sheldrick, 2008), SHELXL2014 (Sheldrick, 2015), SHELXTL2014 (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009) and Mercury (Macrae et al., 2008).

Acknowledgements

This work was supported by Vassar College. X-ray facilities were provided by the US National Science Foundation (grant No. 0521237 to JMT).

References

Bondi, A. (1964). J. Phys. Chem. 68, 441–451 . CrossRef CAS Web of Science Google Scholar
Bruker (2013). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bull, J. A., Mousseau, J. J., Pelletier, G. & Charette, A. B. (2012). Chem. Rev. 112, 2642–2713. CrossRef CAS PubMed Google Scholar
Busto, E., Gotor-Fernandez, V. & Gotor, V. (2005). Tetrahedron Asymmetry, 16, 3427–3425. CrossRef CAS Google Scholar
Desiraju, G. R. & Steiner, T. (1999). In The Weak Hydrogen Bond in Structural Chemistry and Biology. Oxford University Press. Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Freytag, M. & Jones, P. G. (2001). Z. Naturforsch. Teil B, 56, 889–896. CAS Google Scholar
Freytag, M., Jones, P. G., Aherns, B. & Fischer, A. K. (1999). New J. Chem. 23, 1137–1139. CSD CrossRef CAS Google Scholar
Groom, C. R. & Allen, F. H. (2014). Angew. Chem. Int. Ed. 53, 662–671. Web of Science CSD CrossRef CAS Google Scholar
Guo, S., Wang, Y., Sun, C., Li, J., Zou, D., Wu, Y. & Wu, Y. (2013). Tetrahedron Lett. 54, 3233–3237. CrossRef CAS Google Scholar
Hunter, C. A. & Saunders, J. K. M. (1990). J. Am. Chem. Soc. 112, 5525–5534. CrossRef CAS Web of Science Google Scholar
Jelsch, C., Soudani, S. & Ben Nasr, C. (2015). IUCrJ, 2, 327–340. Web of Science CrossRef CAS PubMed IUCr Journals Google Scholar
Kiener, A., Roduit, J.-P. & Glockler, R. (1996). Eur. Patent Appl. EP747486A119961211. Google Scholar
Kubiak, R., Janczak, J. & Śledź, M. (2002). J. Mol. Struct. 610, 59–64. CSD CrossRef CAS Google Scholar
Laing, M., Sparrow, N. & Sommerville, P. (1971). Acta Cryst. B27, 1986–1990. CSD CrossRef IUCr Journals Google Scholar
Lueckheide, M., Rothman, N., Ko, B. & Tanski, J. M. (2013). Polyhedron, 58, 79–84. Web of Science CSD CrossRef CAS Google Scholar
Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Mootz, D. & Wussow, H. G. (1981). J. Chem. Phys. 75, 1517–1522. CSD CrossRef CAS Web of Science Google Scholar
Pedireddi, V. R., Reddy, D. S., Goud, B. S., Craig, D. C., Rae, A. D. & Desiraju, G. R. (1994). J. Chem. Soc. Perkin Trans. 2, pp. 2353–2360. CSD CrossRef Web of Science Google Scholar
Ruetman, S. H. & Taplin, W. H. (1971). US Patent 3591597 A. Google Scholar
Sakamoto, T., Kaneda, S.-I., Nishimura, S. & Yamanaka, H. (1985). Chem. Pharm. Bull. 2, 565–571. CrossRef Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Sheldrick, G. M. (2015). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Tsukamoto, I., Koshio, H., Kuramochi, T., Saitoh, C., Yanai-Inamura, H., Kitada-Nozawa, C., Yamamoto, E., Yatsu, T., Shimada, Y., Sakamoto, S. & Tsukamoto, S.-I. (2009). Bioorg. Med. Chem. 17, 3130–3141. CrossRef PubMed CAS Google Scholar
Veerareddy, A., Surendrareddy, G. & Dubey, P. K. (2011). J. Heterocycl. Chem. 48, 961–964. CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 71| Part 7| July 2015| Pages 852-856

doi:10.1107/S2056989015011767

Open

access

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Search IUCr Journals		doi		Advanced search
Author		volume	page

research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Crystal structures of 4-chloro­pyridine-2-carbo­nitrile and 6-chloro­pyridine-2-carbo­nitrile exhibit different inter­molecular π-stacking, C—H⋯Nnitrile and C—H⋯Npyridine inter­actions

1. Chemical context

2. Structural commentary

3. Supra­molecular features

4. Synthesis and crystallization

5. Refinement

Supporting information

Acknowledgements

References

research communications

Crystal structures of 4-chloropyridine-2-carbonitrile and 6-chloropyridine-2-carbonitrile exhibit different intermolecular π-stacking, C—H⋯N_nitrile and C—H⋯N_pyridine interactions

3. Supramolecular features