2,6-[Bis­(di­methyl­amino)­meth­yl]phenyl­selenenyl chloride/bromide monohydrate

Gupta, A.; Singh, H.B.; Butcher, R.J.

doi:10.1107/S2414314617016340

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 2| Part 11| November 2017| x171634

https://doi.org/10.1107/S2414314617016340

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2,6-[Bis(dimethylamino)methyl]phenylselenenyl chloride/bromide monohydrate

Anand Gupta,^a Harkesh B. Singh ^a and Ray J. Butcher ^b ^*

^aDepartment of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India, and ^bDepartment of Chemistry, Howard University, 525 College Street NW, Washington DC 20059, USA
^*Correspondence e-mail: rbutcher99@yahoo.com

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 28 September 2017; accepted 13 November 2017; online 17 November 2017)

In the title hydrated salt, C₁₂H₁₉N₂Se⁺·Cl_0.44/Br_0.56⁻·H₂O, the halide ions (both with site symmetry 2) have different Cl⁻/Br⁻ occupancies of 0.399 (2)/0.601 (2) and 0.491 (2)/0.509 (2). In the crystal, the cation and anion are linked by an Se⋯X (X = Cl/Br) interaction of length 3.5593 (8) Å. The water molecule and anions are linked by O—H⋯X hydrogen bonds into a staggered chain propagating in the b-axis direction and the packing is consolidated by weak C—H⋯X interactions.

Keywords: crystal structure; selenenyl cation; mixed halide salts.

CCDC reference: 1510426

Structure description

The molecular structure of hydrated molecular salt 3, [C₁₂H₁₉N₂Se]⁺Cl_0.44/Br_0.56⁻·H₂O is shown in Fig. 1. It crystallizes in the monoclinic crystal system with 56% of Br and 46% of Cl in total but distributed over two sites in different ratios [in site 1, the Cl/Br ratio is 0.399 (2)/0.601 (2) and in site 2 the Cl/Br ratio is 0.491 (2)/0.509 (2)]. There have been three previous structures containing the same cation with PF₆⁻ (Fujihara et al., 1995 ), HF₂⁻ (Poleschner & Seppelt, 2004 ) and Br⁻ (Varga et al., 2010 ) as counter-ions. This latter compound is essentially isostructural with 3 but with a stoichiometric amount of Br⁻.

Figure 1
The molecular structure showing 30% displacement ellipsoids. Hydrogen bonds are shown as dashed lines.

The geometry around Se is T-shaped with an N1—Se—N2 angle of 161.38 (7)°. The Se—N bonds give rise to two five-membered chelate rings and the central ring (C1–C6) is essentially planar (r.m.s. deviation = 0.002 Å) with two other atoms approximately in this plane [Se1, 0.065 (2) Å and C7 0.059 (2) Å]. The N1—Se1—N2 axis is twisted by 14.4 (2)° about this plane. The Se—N bond lengths are 2.1836 (17) and 2.1861 (17) Å and the Se⋯Br/Cl distance is 3.559 (3) Å, which is shorter than Σr_vdw (Se, X) 3.75/3.65 Å for Br/Cl, providing a second coordination sphere.

In the extended structure, the water molecule and anions are linked by hydrogen bonds (Table 1) into a staggered chain in the b-axis direction. The packing also features weak C—H⋯Br interactions. In addition there are C—H⋯π interactions, which link the cations into dimers (shown in Fig. 2). The overall packing is shown in Fig. 3.

Table 1
Hydrogen-bond geometry (Å, °)

Cg is the centroid of the C1–C6 ring. X1 = Br1/Cl1; X2 = Br2/Cl2.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1W—H1W2⋯X1ⁱ	0.82 (2)	2.50 (2)	3.315 (2)	177 (4)
O1W—H1W1⋯X2	0.82 (2)	2.44 (2)	3.256 (2)	177 (3)
C7—H7B⋯Br1ⁱⁱ	0.99	2.89	3.869 (2)	171
C7—H7A⋯Cgⁱⁱⁱ	0.99	2.94	3.908 (3)	165
Symmetry codes: (i) $[x+{\script{1\over 2}}, y+{\script{1\over 2}}, z]$ ; (ii) $[x+{\script{3\over 2}}, y+{\script{3\over 2}}, z+1]$ ; (iii) $[-x+{\script{3\over 2}}, -y+{\script{1\over 2}}, -z+1]$ .

Figure 2
Diagram of a pair of cations showing the C—H⋯π interactions linking them into dimeric units. Atomic displacement parameters are at the 30% probability level.

Figure 3
Packing diagram viewed along [100] showing O—H⋯Br and C—H⋯Br interactions generating a staggered chain in the [010] direction.

Synthesis and crystallization

To a stirred solution of 1 (1.25 g, 4.61 mmol) in dry Et₂O (15 ml) at 273 K, n-BuLi (2.88 ml, 4.60 mmol) was added dropwise via syringe under an inert argon atmosphere. After 30 min, the colour of the reaction mixture changed from colourless to yellowish, and elemental Se powder (0.36 g, 4.61 mmol) was added under a full flow of argon. After 6 h stirring at room temperature, saturated NH₄Cl (50 ml) was added and oxygen gas was bubbled for 20 min. The whole mixture was extracted with Et₂O and the organic phase was washed with H₂O, dried over Na₂SO₄ and concentrated by rotary evaporator. The reaction scheme is shown in Fig. 4. The resulting solid was dried over vacuum to afford 3 (0.94 g, 75% yield) as a yellowish solid (m.p. = 427–430 K). Colourless prisms of 3 were obtained by slow diffusion of hexane into a CH₂Cl₂ solution at room temperature. The water molecule of crystallization was presumably absorbed from the atmosphere. ¹H NMR: δ (p.p.m.) 7.20 (s, 3H, ArCH₂), 4.12 (s, 4H, –CH₂), 2.91 (s, 12H, NCH₃). ¹³C NMR: δ (p.p.m.) 132.57, 132.40, 128.42, 125.94, 64.04, 48.98. ⁷⁷Se NMR: δ (p.p.m.) 1201. Analysis calculated (%) for C₁₂H₁₉Cl/BrSeN₂: C 42.67; H 6.34; N 7.95. Found: C 42.52; H 6.34; N 8.26.

Figure 4
Reaction scheme.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. The anions have refined site occupancies of 0.399 (2)/0.601 (2) for Cl1/Br1 and 0.491 (2)/0.509 (2) for Cl2/Br2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₂H₁₉N₂Se⁺·Cl_0.44/Br_0.56⁻·H₂O
M_r	348.45
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	123
a, b, c (Å)	14.7635 (7), 11.2385 (3), 19.4113 (10)
β (°)	115.087 (6)
V (Å³)	2916.9 (3)
Z	8
Radiation type	Cu Kα
μ (mm⁻¹)	5.92
Crystal size (mm)	0.38 × 0.24 × 0.15

Data collection
Diffractometer	Agilent Xcalibur, Ruby, Gemini
Absorption correction	Multi-scan (CrysAlis PRO; Agilent, 2012 ). Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.
T_min, T_max	0.289, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	6566, 2917, 2780
R_int	0.022
(sin θ/λ)_max (Å⁻¹)	0.628

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.029, 0.075, 1.09
No. of reflections	2917
No. of parameters	169
No. of restraints	3
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.67, −0.36
Computer programs: CrysAlis PRO (Agilent, 2012), SHELXS97 and SHELXTL (Sheldrick, 2008 ) and SHELXL2017/1 (Sheldrick, 2015 ).

Structural data

CCDC reference: 1510426

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314617016340/hb4173sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314617016340/hb4173Isup2.hkl

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Agilent, 2012); cell refinement: CrysAlis PRO (Agilent, 2012); data reduction: CrysAlis PRO (Agilent, 2012); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2017/1 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

2,6-[Bis(dimethylamino)methyl]phenylselenenyl chloride/bromide monohydrate top

Crystal data top

C₁₂H₁₉N₂Se⁺·Cl0.44/Br_0.56⁻·H₂O	F(000) = 1408
M_r = 348.45	D_x = 1.587 Mg m⁻³
Monoclinic, C2/c	Cu Kα radiation, λ = 1.54184 Å
a = 14.7635 (7) Å	Cell parameters from 4254 reflections
b = 11.2385 (3) Å	θ = 5.0–75.3°
c = 19.4113 (10) Å	µ = 5.92 mm⁻¹
β = 115.087 (6)°	T = 123 K
V = 2916.9 (3) Å³	Prism, colouress
Z = 8	0.38 × 0.24 × 0.15 mm

Data collection top

Agilent Xcalibur, Ruby, Gemini diffractometer	2780 reflections with I > 2σ(I)
Detector resolution: 10.5081 pixels mm^-1	R_int = 0.022
ω scans	θ_max = 75.4°, θ_min = 5.0°
Absorption correction: multi-scan (CrysAlisPro; Agilent, 2012). Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.	h = −18→16
T_min = 0.289, T_max = 1.000	k = −14→9
6566 measured reflections	l = −23→24
2917 independent reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.029	Hydrogen site location: mixed
wR(F²) = 0.075	H atoms treated by a mixture of independent and constrained refinement
S = 1.09	w = 1/[σ²(F_o²) + (0.0475P)² + 1.6414P] where P = (F_o² + 2F_c²)/3
2917 reflections	(Δ/σ)_max = 0.002
169 parameters	Δρ_max = 0.67 e Å⁻³
3 restraints	Δρ_min = −0.36 e Å⁻³

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. The H atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.95–0.99 Å. U_iso(H) = xU_eq(C), where x = 1.5 for methyl H atoms and 1.2 for all other C-bound H atoms. The hydrogen atoms attached to water were refined isotropically.

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Se1	0.75366 (2)	0.43673 (2)	0.62278 (2)	0.01726 (10)
Br1	0.500000	0.48925 (4)	0.750000	0.02635 (17)	0.601 (4)
Br2	1.000000	0.52385 (4)	0.750000	0.0332 (2)	0.509 (5)
Cl1	0.500000	0.48925 (4)	0.750000	0.02635 (17)	0.399 (4)
Cl2	1.000000	0.52385 (4)	0.750000	0.0332 (2)	0.491 (5)
N1	0.70609 (13)	0.51175 (15)	0.50884 (10)	0.0188 (3)
N2	0.75927 (13)	0.32516 (15)	0.71661 (9)	0.0193 (3)
O1W	1.12342 (16)	0.75325 (18)	0.84692 (10)	0.0373 (4)
H1W1	1.091 (2)	0.696 (2)	0.8234 (18)	0.038 (9)*
H1W2	1.092 (3)	0.811 (2)	0.824 (2)	0.053 (11)*
C1	0.65376 (14)	0.32552 (16)	0.56659 (11)	0.0166 (4)
C2	0.62026 (14)	0.32262 (17)	0.48798 (11)	0.0184 (4)
C3	0.54910 (16)	0.23754 (18)	0.44704 (12)	0.0218 (4)
H3A	0.525043	0.233201	0.393301	0.026*
C4	0.51333 (16)	0.15873 (18)	0.48529 (13)	0.0233 (4)
H4A	0.464577	0.101073	0.457183	0.028*
C5	0.54826 (15)	0.16341 (17)	0.56450 (12)	0.0210 (4)
H5A	0.523723	0.108918	0.589965	0.025*
C6	0.61907 (15)	0.24827 (17)	0.60566 (12)	0.0174 (4)
C7	0.66883 (15)	0.40967 (19)	0.45535 (11)	0.0207 (4)
H7A	0.725058	0.371125	0.448937	0.025*
H7B	0.619757	0.437687	0.404953	0.025*
C8	0.62515 (17)	0.5973 (2)	0.49817 (13)	0.0259 (4)
H8A	0.601274	0.633182	0.447481	0.039*
H8B	0.650705	0.659832	0.536903	0.039*
H8C	0.569814	0.555742	0.503041	0.039*
C9	0.79051 (16)	0.57326 (19)	0.50219 (13)	0.0239 (4)
H9A	0.768046	0.606851	0.451002	0.036*
H9B	0.844699	0.516366	0.511282	0.036*
H9C	0.814757	0.637367	0.539886	0.036*
C10	0.65818 (16)	0.27041 (18)	0.68983 (12)	0.0212 (4)
H10A	0.612571	0.324523	0.700279	0.025*
H10B	0.662383	0.194509	0.716907	0.025*
C11	0.83732 (17)	0.2335 (2)	0.73130 (13)	0.0259 (4)
H11A	0.841875	0.183212	0.773882	0.039*
H11B	0.901881	0.272361	0.743994	0.039*
H11C	0.819892	0.184354	0.685755	0.039*
C12	0.78343 (18)	0.3997 (2)	0.78520 (12)	0.0265 (4)
H12A	0.785606	0.349623	0.827207	0.040*
H12B	0.731980	0.461028	0.774246	0.040*
H12C	0.848667	0.437680	0.799471	0.040*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Se1	0.01777 (14)	0.01528 (13)	0.01697 (13)	−0.00190 (7)	0.00566 (9)	−0.00137 (7)
Br1	0.0248 (2)	0.0202 (2)	0.0300 (2)	0.000	0.00769 (17)	0.000
Br2	0.0205 (3)	0.0250 (3)	0.0441 (3)	0.000	0.0038 (2)	0.000
Cl1	0.0248 (2)	0.0202 (2)	0.0300 (2)	0.000	0.00769 (17)	0.000
Cl2	0.0205 (3)	0.0250 (3)	0.0441 (3)	0.000	0.0038 (2)	0.000
N1	0.0184 (8)	0.0187 (8)	0.0194 (8)	0.0009 (6)	0.0080 (6)	0.0018 (6)
N2	0.0236 (8)	0.0171 (7)	0.0156 (7)	0.0002 (7)	0.0069 (6)	−0.0005 (6)
O1W	0.0454 (11)	0.0365 (10)	0.0249 (8)	−0.0029 (8)	0.0100 (8)	0.0004 (7)
C1	0.0145 (8)	0.0120 (7)	0.0197 (9)	0.0010 (7)	0.0039 (7)	−0.0019 (7)
C2	0.0175 (9)	0.0161 (8)	0.0193 (9)	0.0040 (7)	0.0056 (7)	0.0011 (7)
C3	0.0197 (9)	0.0204 (9)	0.0196 (9)	0.0028 (8)	0.0027 (8)	−0.0026 (7)
C4	0.0197 (9)	0.0166 (9)	0.0280 (10)	−0.0001 (7)	0.0047 (8)	−0.0044 (8)
C5	0.0212 (9)	0.0143 (8)	0.0271 (10)	0.0010 (7)	0.0100 (8)	0.0011 (7)
C6	0.0173 (9)	0.0141 (8)	0.0202 (9)	0.0033 (7)	0.0075 (8)	0.0002 (7)
C7	0.0218 (9)	0.0205 (9)	0.0175 (9)	0.0021 (8)	0.0061 (7)	0.0003 (7)
C8	0.0274 (10)	0.0197 (9)	0.0338 (11)	0.0069 (9)	0.0160 (9)	0.0066 (8)
C9	0.0213 (10)	0.0251 (10)	0.0276 (10)	−0.0031 (8)	0.0126 (8)	0.0035 (8)
C10	0.0246 (10)	0.0194 (9)	0.0197 (9)	−0.0010 (8)	0.0096 (8)	0.0001 (7)
C11	0.0268 (11)	0.0256 (10)	0.0225 (10)	0.0060 (9)	0.0078 (9)	0.0022 (8)
C12	0.0340 (11)	0.0263 (10)	0.0185 (9)	−0.0039 (9)	0.0104 (8)	−0.0058 (8)

Geometric parameters (Å, º) top

Se1—C1	1.8875 (19)	C5—C6	1.390 (3)
Se1—N2	2.1836 (17)	C5—H5A	0.9500
Se1—N1	2.1861 (17)	C6—C10	1.505 (3)
N1—C9	1.478 (3)	C7—H7A	0.9900
N1—C8	1.479 (3)	C7—H7B	0.9900
N1—C7	1.487 (3)	C8—H8A	0.9800
N2—C11	1.480 (3)	C8—H8B	0.9800
N2—C12	1.483 (3)	C8—H8C	0.9800
N2—C10	1.489 (3)	C9—H9A	0.9800
O1W—H1W1	0.818 (18)	C9—H9B	0.9800
O1W—H1W2	0.819 (18)	C9—H9C	0.9800
C1—C6	1.386 (3)	C10—H10A	0.9900
C1—C2	1.391 (3)	C10—H10B	0.9900
C2—C3	1.393 (3)	C11—H11A	0.9800
C2—C7	1.503 (3)	C11—H11B	0.9800
C3—C4	1.395 (3)	C11—H11C	0.9800
C3—H3A	0.9500	C12—H12A	0.9800
C4—C5	1.400 (3)	C12—H12B	0.9800
C4—H4A	0.9500	C12—H12C	0.9800

C1—Se1—N2	81.13 (8)	N1—C7—H7A	110.1
C1—Se1—N1	80.42 (8)	C2—C7—H7A	110.1
N2—Se1—N1	161.38 (7)	N1—C7—H7B	110.1
C9—N1—C8	110.17 (17)	C2—C7—H7B	110.1
C9—N1—C7	112.08 (17)	H7A—C7—H7B	108.4
C8—N1—C7	111.48 (17)	N1—C8—H8A	109.5
C9—N1—Se1	110.34 (13)	N1—C8—H8B	109.5
C8—N1—Se1	106.65 (13)	H8A—C8—H8B	109.5
C7—N1—Se1	105.89 (12)	N1—C8—H8C	109.5
C11—N2—C12	110.41 (17)	H8A—C8—H8C	109.5
C11—N2—C10	111.28 (17)	H8B—C8—H8C	109.5
C12—N2—C10	111.76 (17)	N1—C9—H9A	109.5
C11—N2—Se1	108.14 (13)	N1—C9—H9B	109.5
C12—N2—Se1	109.52 (13)	H9A—C9—H9B	109.5
C10—N2—Se1	105.55 (12)	N1—C9—H9C	109.5
H1W1—O1W—H1W2	105 (3)	H9A—C9—H9C	109.5
C6—C1—C2	122.94 (18)	H9B—C9—H9C	109.5
C6—C1—Se1	118.56 (15)	N2—C10—C6	108.28 (16)
C2—C1—Se1	118.48 (15)	N2—C10—H10A	110.0
C1—C2—C3	118.25 (19)	C6—C10—H10A	110.0
C1—C2—C7	115.85 (17)	N2—C10—H10B	110.0
C3—C2—C7	125.84 (19)	C6—C10—H10B	110.0
C2—C3—C4	119.73 (19)	H10A—C10—H10B	108.4
C2—C3—H3A	120.1	N2—C11—H11A	109.5
C4—C3—H3A	120.1	N2—C11—H11B	109.5
C3—C4—C5	120.94 (19)	H11A—C11—H11B	109.5
C3—C4—H4A	119.5	N2—C11—H11C	109.5
C5—C4—H4A	119.5	H11A—C11—H11C	109.5
C6—C5—C4	119.61 (19)	H11B—C11—H11C	109.5
C6—C5—H5A	120.2	N2—C12—H12A	109.5
C4—C5—H5A	120.2	N2—C12—H12B	109.5
C1—C6—C5	118.53 (19)	H12A—C12—H12B	109.5
C1—C6—C10	115.46 (17)	N2—C12—H12C	109.5
C5—C6—C10	125.89 (19)	H12A—C12—H12C	109.5
N1—C7—C2	108.02 (16)	H12B—C12—H12C	109.5

N2—Se1—C1—C6	11.53 (15)	C2—C1—C6—C10	−175.68 (17)
N1—Se1—C1—C6	−165.94 (16)	Se1—C1—C6—C10	6.2 (2)
N2—Se1—C1—C2	−166.72 (16)	C4—C5—C6—C1	−0.6 (3)
N1—Se1—C1—C2	15.81 (14)	C4—C5—C6—C10	175.25 (19)
C6—C1—C2—C3	−0.4 (3)	C9—N1—C7—C2	154.58 (17)
Se1—C1—C2—C3	177.74 (15)	C8—N1—C7—C2	−81.4 (2)
C6—C1—C2—C7	−177.69 (18)	Se1—N1—C7—C2	34.21 (17)
Se1—C1—C2—C7	0.5 (2)	C1—C2—C7—N1	−25.4 (2)
C1—C2—C3—C4	0.3 (3)	C3—C2—C7—N1	157.57 (19)
C7—C2—C3—C4	177.24 (19)	C11—N2—C10—C6	−82.82 (19)
C2—C3—C4—C5	−0.3 (3)	C12—N2—C10—C6	153.24 (17)
C3—C4—C5—C6	0.5 (3)	Se1—N2—C10—C6	34.26 (17)
C2—C1—C6—C5	0.6 (3)	C1—C6—C10—N2	−28.9 (2)
Se1—C1—C6—C5	−177.58 (14)	C5—C6—C10—N2	155.18 (19)

Hydrogen-bond geometry (Å, º) top

Cg is the centroid of the C1–C6 ring.

D—H···A	D—H	H···A	D···A	D—H···A
O1W—H1W2···X1ⁱ	0.82 (2)	2.50 (2)	3.315 (2)	177 (4)
O1W—H1W1···X2	0.82 (2)	2.44 (2)	3.256 (2)	177 (3)
C7—H7B···Br1ⁱⁱ	0.99	2.89	3.869 (2)	171
C7—H7A···Cgⁱⁱⁱ	0.99	2.94	3.908 (3)	165

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

Funding information

RJB is grateful for the NSF award 1205608, Partnership for Reduced Dimensional Materials for partial funding of this research as well as the Howard University Nanoscience Facility access to liquid nitrogen. RJB acknowledges the NSF MRI program (grant No. CHE-0619278) for funds to purchase an X-ray diffractometer. HBS is grateful to Department of Science and Technology, New Delhi, for a J. C. Bose Fellowship.

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