A new polymorph of phenyl­selenium trichloride

A second polymorph of phenyl­selenium trichloride, PhSeCl₃ or C₆H₅Cl₃Se, is disclosed, which is comprised of asymmetric chlorine-bridged noncovalent dimer units rather than polymeric chains. These dimers are each weakly bound to an adjacent dimer through noncovalent Se...Cl bonding inter­actions. Phenyl rings within each dimer are oriented in a syn fashion. Density functional theory (DFT) calculations reveal that the putative anti isomer is within 5 kJ mol⁻¹ of the experimentally observed form. This structure represents the first additional polymorph discovered for an organoselenium trihalide compound.

Computing details

Data collection: APEX3 (Bruker, 2016; cell refinement: SAINT (Bruker, 2016); data reduction: SAINT (Bruker, 2016; program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Phenylselenium trichloride

Crystal data

C6H5Cl3Se	Z = 4
Mr = 262.41	F(000) = 504
Triclinic, P1	Dx = 2.037 Mg m^−3
a = 8.6245 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.5342 (4) Å	Cell parameters from 8248 reflections
c = 11.7229 (5) Å	θ = 2.6–32.6°
α = 78.332 (2)°	µ = 5.24 mm^−1
β = 77.789 (2)°	T = 150 K
γ = 66.341 (2)°	Prism, clear colourless
V = 855.50 (6) Å^3	0.53 × 0.52 × 0.35 mm

Data collection

Bruker APEXII CCD diffractometer	3470 reflections with I > 2σ(I)
φ and ω scans	Rint = 0.037
Absorption correction: numerical (SADABS; Bruker, 2016)	θmax = 28.7°, θmin = 2.6°
Tmin = 0.456, Tmax = 0.747	h = −11→11
15455 measured reflections	k = −12→12
4426 independent reflections	l = −15→15

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.029	w = 1/[σ^2(Fo^2) + (0.0095P)^2 + 0.5686P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.051	(Δ/σ)max = 0.001
S = 1.05	Δρmax = 0.46 e Å^−3
4426 reflections	Δρmin = −0.57 e Å^−3
182 parameters	Extinction correction: SHELXL2018 (Sheldrick, 2015b), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0114 (3)
Primary atom site location: dual

Special details

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.

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

	x	y	z	Uiso*/Ueq
Se1	0.46873 (3)	0.37174 (3)	0.37701 (2)	0.01526 (7)
Se2	0.33135 (3)	0.82730 (3)	0.29123 (2)	0.01719 (7)
Cl4	0.23956 (8)	0.64558 (7)	0.46326 (5)	0.02005 (13)
Cl1	0.57258 (8)	0.55087 (8)	0.21325 (5)	0.02304 (14)
Cl3	0.37555 (9)	0.22740 (8)	0.53285 (6)	0.02807 (16)
Cl2	0.67527 (8)	0.17097 (8)	0.30719 (6)	0.02984 (16)
Cl5	0.15514 (9)	1.02879 (8)	0.37443 (6)	0.03339 (17)
Cl6	0.44520 (9)	0.96373 (8)	0.14372 (6)	0.03359 (17)
C1	0.3008 (3)	0.3840 (3)	0.2832 (2)	0.0155 (5)
C7	0.1696 (3)	0.8222 (3)	0.1993 (2)	0.0170 (5)
C8	0.0049 (3)	0.8412 (3)	0.2539 (2)	0.0199 (5)
H8	−0.029076	0.855370	0.334641	0.024*
C2	0.1329 (3)	0.4140 (3)	0.3366 (2)	0.0185 (5)
H2	0.100984	0.424952	0.417965	0.022*
C6	0.3511 (3)	0.3669 (3)	0.1649 (2)	0.0213 (5)
H6	0.466331	0.347356	0.129613	0.026*
C9	−0.1095 (3)	0.8390 (3)	0.1870 (2)	0.0235 (6)
H9	−0.223387	0.852156	0.222208	0.028*
C4	0.0613 (3)	0.4096 (3)	0.1506 (2)	0.0218 (6)
H4	−0.021439	0.418381	0.104667	0.026*
C3	0.0130 (3)	0.4276 (3)	0.2690 (2)	0.0215 (6)
H3	−0.102844	0.449365	0.303758	0.026*
C12	0.2236 (3)	0.7984 (3)	0.0828 (2)	0.0229 (6)
H12	0.337873	0.784085	0.047616	0.027*
C10	−0.0587 (3)	0.8180 (3)	0.0700 (2)	0.0253 (6)
H10	−0.138341	0.818728	0.024752	0.030*
C5	0.2290 (3)	0.3791 (3)	0.0991 (2)	0.0248 (6)
H5	0.261162	0.366247	0.018056	0.030*
C11	0.1075 (4)	0.7958 (3)	0.0183 (2)	0.0281 (6)
H11	0.142480	0.778644	−0.061869	0.034*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Se1	0.01433 (13)	0.01787 (13)	0.01336 (13)	−0.00551 (10)	−0.00342 (10)	−0.00121 (10)
Se2	0.01727 (13)	0.01849 (14)	0.01750 (14)	−0.00836 (11)	−0.00562 (10)	0.00074 (10)
Cl4	0.0202 (3)	0.0267 (3)	0.0139 (3)	−0.0100 (3)	−0.0013 (2)	−0.0028 (2)
Cl1	0.0160 (3)	0.0320 (4)	0.0201 (3)	−0.0105 (3)	0.0004 (2)	−0.0012 (3)
Cl3	0.0340 (4)	0.0354 (4)	0.0197 (3)	−0.0209 (3)	−0.0104 (3)	0.0092 (3)
Cl2	0.0234 (3)	0.0235 (3)	0.0337 (4)	0.0028 (3)	−0.0049 (3)	−0.0083 (3)
Cl5	0.0405 (4)	0.0216 (3)	0.0387 (4)	−0.0062 (3)	−0.0105 (3)	−0.0118 (3)
Cl6	0.0313 (4)	0.0375 (4)	0.0365 (4)	−0.0235 (3)	−0.0116 (3)	0.0146 (3)
C1	0.0184 (12)	0.0160 (12)	0.0148 (12)	−0.0078 (10)	−0.0057 (10)	−0.0016 (10)
C7	0.0180 (12)	0.0139 (12)	0.0189 (13)	−0.0043 (10)	−0.0083 (10)	0.0002 (10)
C8	0.0166 (12)	0.0199 (13)	0.0199 (13)	−0.0030 (10)	−0.0034 (10)	−0.0028 (11)
C2	0.0199 (13)	0.0221 (13)	0.0132 (12)	−0.0075 (11)	−0.0009 (10)	−0.0041 (10)
C6	0.0192 (13)	0.0285 (14)	0.0160 (13)	−0.0094 (11)	0.0012 (10)	−0.0056 (11)
C9	0.0156 (13)	0.0227 (14)	0.0313 (15)	−0.0049 (11)	−0.0084 (11)	−0.0011 (12)
C4	0.0279 (15)	0.0236 (14)	0.0198 (13)	−0.0138 (12)	−0.0111 (11)	0.0012 (11)
C3	0.0182 (13)	0.0258 (14)	0.0223 (14)	−0.0105 (11)	−0.0036 (11)	−0.0018 (11)
C12	0.0192 (13)	0.0277 (14)	0.0203 (13)	−0.0070 (11)	−0.0022 (11)	−0.0046 (11)
C10	0.0280 (14)	0.0209 (14)	0.0310 (15)	−0.0082 (12)	−0.0154 (12)	−0.0026 (12)
C5	0.0301 (15)	0.0333 (16)	0.0150 (13)	−0.0154 (13)	−0.0019 (11)	−0.0062 (11)
C11	0.0339 (16)	0.0312 (16)	0.0195 (14)	−0.0100 (13)	−0.0074 (12)	−0.0052 (12)

Geometric parameters (Å, º)

Se1—Cl4^i	3.3760 (6)	C8—C9	1.393 (3)
Se1—Cl4	2.7975 (7)	C2—H2	0.9500
Se1—Cl1	2.5648 (7)	C2—C3	1.382 (3)
Se1—Cl3	2.2643 (7)	C6—H6	0.9500
Se1—Cl2	2.1881 (7)	C6—C5	1.388 (3)
Se1—C1	1.951 (2)	C9—H9	0.9500
Se2—Cl4	2.5900 (6)	C9—C10	1.378 (4)
Se2—Cl1	2.8070 (7)	C4—H4	0.9500
Se2—Cl3^i	3.4099 (7)	C4—C3	1.388 (3)
Se2—Cl5	2.1769 (7)	C4—C5	1.380 (4)
Se2—Cl6	2.2458 (7)	C3—H3	0.9500
Se2—C7	1.955 (2)	C12—H12	0.9500
C1—C2	1.389 (3)	C12—C11	1.387 (3)
C1—C6	1.385 (3)	C10—H10	0.9500
C7—C8	1.384 (3)	C10—C11	1.381 (4)
C7—C12	1.380 (3)	C5—H5	0.9500
C8—H8	0.9500	C11—H11	0.9500
Cl4—Se1—Cl4^i	90.204 (17)	C6—C1—C2	121.9 (2)
Cl1—Se1—Cl4	84.71 (2)	C8—C7—Se2	118.66 (18)
Cl1—Se1—Cl4^i	89.433 (18)	C12—C7—Se2	119.06 (18)
Cl3—Se1—Cl4^i	87.29 (2)	C12—C7—C8	122.3 (2)
Cl3—Se1—Cl4	91.45 (2)	C7—C8—H8	121.0
Cl3—Se1—Cl1	174.95 (2)	C7—C8—C9	118.0 (2)
Cl2—Se1—Cl4^i	83.89 (2)	C9—C8—H8	121.0
Cl2—Se1—Cl4	172.03 (2)	C1—C2—H2	120.7
Cl2—Se1—Cl1	89.87 (3)	C3—C2—C1	118.7 (2)
Cl2—Se1—Cl3	93.60 (3)	C3—C2—H2	120.7
C1—Se1—Cl4	89.59 (7)	C1—C6—H6	120.8
C1—Se1—Cl4^i	179.21 (7)	C1—C6—C5	118.4 (2)
C1—Se1—Cl1	89.78 (7)	C5—C6—H6	120.8
C1—Se1—Cl3	93.48 (7)	C8—C9—H9	119.7
C1—Se1—Cl2	96.25 (7)	C10—C9—C8	120.5 (2)
Cl4—Se2—Cl1	84.06 (2)	C10—C9—H9	119.7
Cl4—Se2—Cl3^i	81.751 (18)	C3—C4—H4	119.8
Cl1—Se2—Cl3^i	83.668 (19)	C5—C4—H4	119.8
Cl5—Se2—Cl4	90.83 (3)	C5—C4—C3	120.3 (2)
Cl5—Se2—Cl1	172.41 (3)	C2—C3—C4	120.2 (2)
Cl5—Se2—Cl3^i	90.06 (2)	C2—C3—H3	119.9
Cl5—Se2—Cl6	94.38 (3)	C4—C3—H3	119.9
Cl6—Se2—Cl4	172.72 (3)	C7—C12—H12	120.7
Cl6—Se2—Cl1	90.24 (3)	C7—C12—C11	118.6 (2)
Cl6—Se2—Cl3^i	93.14 (2)	C11—C12—H12	120.7
C7—Se2—Cl4	90.64 (7)	C9—C10—H10	119.8
C7—Se2—Cl1	89.74 (7)	C9—C10—C11	120.3 (2)
C7—Se2—Cl3^i	170.39 (7)	C11—C10—H10	119.8
C7—Se2—Cl5	95.94 (7)	C6—C5—H5	119.8
C7—Se2—Cl6	93.87 (7)	C4—C5—C6	120.5 (2)
Se2—Cl4—Se1	95.36 (2)	C4—C5—H5	119.8
Se1—Cl1—Se2	95.70 (2)	C12—C11—H11	119.9
C2—C1—Se1	118.78 (17)	C10—C11—C12	120.3 (2)
C6—C1—Se1	119.29 (18)	C10—C11—H11	119.9

Symmetry code: (i) −x+1, −y+1, −z+1.