1,3-Bis[2-(dimethyl­amino­meth­yl)­phen­yl]­tris­elenide

The title compound, C₁₈H₂₄N₂Se₃, consists of discrete mol­ecules; owing to the presence of strong intra­molecular N...Se inter­actions [N...Se = 2.671 (4) and 2.873 (4) Å], the chalcogen Se atoms of the angular Se₃ chain exhibit different coordination geometries, i.e. the terminal Se atoms are tricoordinated and exhibit a T-shaped environment of the CNSe₂ core [N...Se—Se = 173.73 (9) and 172.29 (9)°], while the central Se atom is dicoordinated to the other two Se atoms, with an Se—Se—Se angle of 108.32 (2)°.

S1. Comment

Our research interests have focused on the synthesis, structural characterization and chemical reactivity of new RSe and RTe derivatives containing aryl groups with pendant arms, e.g. 2-(Me₂NCH₂)C₆H₄, 2-[O(CH₂CH₂)₂NCH₂]C₆H₄– and 2-[MeN(CH₂CH₂)₂NCH₂]C₆H₄– groups (Drake et al., 2001a,b; Deleanu et al., 2002; Kulcsar et al., 2005, 2007). Both organic groups attached to the Se atoms form intramolecular N···Se interactions, resulting in an increase in the coordination number at the Se1 and Se3 atoms to three (Fig. 1). Some diorganotriselenides (R₂Se₃) of the type R—Se—Se—Se—R [R = Bu^t₂CH (McKinnon et al., 1978), 2,4-Cl₂C₆H₃ (Hansen et al., 1989), (Me₃Si)₃C (Jones & Jeske, 2004), 2-(2-phenyl-5,6-dihydro-4H-1,3-oxazinyl) (Kumar et al., 2004), 4-(phenylamino)quinazolin-2-yl (Atanassov et al., 2004), 2,6-(2,4,6-Prⁱ₃C₆H₂)₂C₆H₃ (Krumm et al., 2005), (Me₂PhSi)₃C (Klapötke et al., 2006) and (Me₂PhSi)₂ClC (Klapötke et al., 2007)] have already been reported.

In the title compound, (I), the coordination geometry around the central Se atom is pseudo-tetrahedral [Se1—Se2—Se3 = 108.32 (3)°] (Table 1) with two positions occupied by the two lone pairs of electrons, while the other two chalcogen Se atoms have distorted T-shaped coordination geometries [N1···Se1—Se2 = 173.73 (9)° and Se2—Se3···N2 = 172.29 (9)°]. The two N···Se distances are considerably different [N1···Se1 = 2.671 (4) Å and N2···Se3 = 2.873 (4) Å] and larger than the sum of the covalent radii [r_cov(Se,N) = 1.87 Å], but significantly shorter than the sum of the corresponding van der Waals radii [r_vdW(Se,N) = 3.54 Å] (Emsley, 1993). These distances are in the range 2.61–2.97 Å observed for intramolecular N···Se interactions in R₂Se₂ {e.g. bis[(2-dimethylaminomethyl)phenyl]diselenide (Kaur et al., 1996), [5-Me-2-(4-MeC₆H₄N N)C₆H₃]₂Se₂ (Jones et al., 1996), bis[8-(dimethylamino)-1-naphthyl]diselenide (Mugesh et al., 2001, 2002), bis[2-(4,4-dimethyl-2-oxazolinyl)phenyl]diselenide, bis[2-(4-ethyl-2-oxazolinyl)phenyl]diselenide (Mugesh et al., 1998, 2001), bis[2-{(4S,5S)-4-hydroxymethyl-5-phenyloxazolin-2-yl}phenyl]δiselenide (Miyake et al., 2002), bis[3-(4,5-dihydro-4,4-dimethyl-1,3-oxazol-2-yl)-4-(3,5-dimethylphenyl)-\2-naphthyl]diselenide (Kandasamy et al., 2004), bis[2-(morfolin-1-ylmethyl)phenyl]diselenide and bis[2-(4-methylpiperazin-1-ylmethyl)phenyl]diselenide (Kulcsar et al., 2007)}. However, they are longer than those in the known R₂Se₃ [R = 2-(2-phenyl-5,6-dihydro-4H-1,3-oxazinyl)] derivative [N···Se = 2.562 (18) and 2.569 (14) Å; Kumar et al., 2004]. There are two additional C—H···Se2 intramolecular contacts (Table 2), which are ca 0.3° shorter than the sum of the H/Se contact radii (Fig. 2a).

In spite of the asymmetry in the Se···N distances, the Se—Se bond lengths in (I) are only slightly different [Se1—Se2 = 2.3545 (6) Å and Se2—Se3 = 2.3372 (7) Å] and fall in the range found for R₂Se₂ with aromatic groups with pendant arms, i.e. 2.32–2.38 Å, or the previously mentioned diorganotrichalcogenides R₂Se₃.

The two (C,N)SeSe cores are distorted as a result of the small bite of the organic ligand [C1—Se1···N1 = 76.58 (14)° and C10—Se3···N2 74.12 (15)°], the values diminished at the expense of the enlarged C—Se—Se angles [C1—Se1—Se2 = 102.65 (12)° and C10—Se3—Se2 = 102.73 (12)°]. The phenyl rings are twisted with a C1—Se1—Se3—C10 torsion angle of -143.65 (18)°. The Se—Se—Se angle [108.32 (3)°] is in the range for reported triselenides [99.68 (6)–111.16 (3)°]. The conformation of the C—Se—Se—C skeleton in diorganodichalcogenides can be discussed in terms of `cisoid' (C—Se—Se—C < 90°) and `transoid' conformations (C—Se—Se—C > 90°). For the reported R₂Se₂, both conformations were found, i.e. the C—Se—Se—C torsion angle is 80.9° in [2-{O(CH₂CH₂)₂NCH₂}C₆H₄]₂Se₂ (cisoid) and 114.0° in [2-{MeN(CH₂CH₂)₂NCH₂}C₆H₄]₂Se₂ (transoid) (Kulcsar et al., 2007). In (I), an overall transoid conformation can be assumed by C1—Se1—Se3—C10 having a torsion angle -143.65 (18)°.

The intramolecular N···Se interactions induce planar chirality in the molecule, since the SeC₃N rings are not planar but folded along the Se1···C_methylene axis, with the N atom lying out of the best plane defined by the residual SeC₃ system. Similar behavior was observed in related RSe systems (Kulcsar et al., 2005, 2007). As a consequence, the compound crystallizes as a racemate, i.e. a mixture of R_N1R_N2 and S_N1S_N2 isomers [with the aromatic ring and the N atom as chiral plane and pivot atom, respectively (IUPAC, 1979)].

As with the related [2-(Me₂NCH₂)C₆H₄]₂Se₂ derivative, no short intermolecular interactions were found in (I), though the alkyl CH groups interact with a neighbouring aromatic C₆ ring at contact distances (Table 2). In the structure of the analogous R₂Te₂ compound, [2-(Me₂NCH₂)C₆H₄]₂Te₂, contains discrete dimer associations of pairs of R_N1S_N2- and S_N1R_N2-[2-(Me₂NCH₂)C₆H₄]₂Te₂ isomers built through π—Te···Ph interactions established between atom Te2 of one molecule and the aromatic ring attached to atom Te1 of the other molecule [Te2···Ph_centroid = 3.750 (1) Å; Drake et al., 2001a, 2001b (please specify)].

Related literature

For related literature, see: Atanassov et al. (2004); Deleanu et al. (2002); Drake et al. (2001a,b); Hansen et al. (1989); Jones & Jeske (2004); Jones & Ramirez de Arellano (1996); Kandasamy et al. (2004); Kaur et al. (1996); Klapötke et al. (2006, 2007); Krumm et al. (2005); Kulcsar et al. (2005, 2007); Kumar et al. (2004); Miyake et al. (2002); Mugesh et al. (1998, 2001, 2002).

S2. Experimental

A few crystals of the title compound, (I), were isolated as a by-product in the synthesis of [2-(Me₂NCH₂)C₆H₄]₂Se₂, as a result of insertion of some residual elemental Se in the Se—Se bond of the major [2-(Me₂NCH₂)C₆H₄]₂Se₂ product (Scheme 2). Single crystals suitable for X-ray diffraction were obtained from a CHCl₃/n-hexane mixture.

S3. Refinement

All H atoms were placed in calculated positions and refined using a riding model [C—H = 0.93–0.97 Å, and U_iso(H) = 1.5U_eq(C) for methyl H and U_iso(H) = 1.2U_eq(C) for aryl H]. The methyl groups were allowed to rotate but not to tip.

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SAINT-Plus (Bruker, 2000); data reduction: SAINT-Plus (Bruker, 2000); program(s) used to solve structure: SHELXTL (Bruker, 2001); program(s) used to refine structure: SHELXTL (Bruker, 2001); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2007).

Figures

	Fig. 1. : A view of (I), with the atomic numbering scheme at 30% probability displacement ellipsoids. H atoms are drawn as spheres of arbitrary radii.
	Fig. 2. : (a) A view of the two intramolecular C—H···Se2 contacts in (I). (b) A view of the intramolecular and intermolecular contacts between a pair of molecules in (I) (with atoms drawn as their van der Waals spheres).

1,3-Bis[2-(Dimethylaminomethyl)phenyl]triselenide

Crystal data

C18H24N2Se3	F(000) = 992
Mr = 505.27	Dx = 1.683 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3850 reflections
a = 13.5307 (12) Å	θ = 2.5–23.5°
b = 9.8246 (9) Å	µ = 5.53 mm^−1
c = 16.0701 (14) Å	T = 297 K
β = 111.013 (2)°	Block, colourless
V = 1994.2 (3) Å^3	0.24 × 0.17 × 0.12 mm
Z = 4

Data collection

Bruker SMART CCD diffractometer	3509 independent reflections
Radiation source: fine-focus sealed tube	2961 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.048
ϕ and ω scans	θmax = 25.0°, θmin = 2.5°
Absorption correction: multi-scan (SHELXTL; Bruker, 2001)	h = −16→16
Tmin = 0.324, Tmax = 0.515	k = −11→11
18693 measured reflections	l = −19→19

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)] = 0.041	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.084	H-atom parameters constrained
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0281P)^2 + 1.5451P] where P = (Fo^2 + 2Fc^2)/3
3509 reflections	(Δ/σ)max < 0.001
212 parameters	Δρmax = 0.46 e Å^−3
0 restraints	Δρmin = −0.62 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
C1	−0.0222 (3)	0.2445 (4)	−0.0499 (3)	0.0385 (10)
C2	−0.0964 (3)	0.1431 (4)	−0.0875 (3)	0.0414 (10)
C3	−0.1213 (4)	0.1123 (5)	−0.1766 (3)	0.0561 (13)
H3	−0.1717	0.0457	−0.2028	0.067*
C4	−0.0732 (4)	0.1779 (6)	−0.2273 (3)	0.0687 (15)
H4	−0.0895	0.1542	−0.2868	0.082*
C5	−0.0008 (4)	0.2788 (6)	−0.1897 (3)	0.0632 (14)
H5	0.0309	0.3248	−0.2241	0.076*
C6	0.0253 (3)	0.3125 (4)	−0.1007 (3)	0.0472 (11)
H6	0.0746	0.3807	−0.0753	0.057*
C7	−0.1447 (3)	0.0620 (4)	−0.0331 (3)	0.0509 (12)
H7A	−0.2103	0.0217	−0.0724	0.061*
H7B	−0.0970	−0.0116	−0.0040	0.061*
C8	−0.2525 (4)	0.2375 (5)	−0.0035 (3)	0.0580 (13)
H8A	−0.2393	0.2921	−0.0480	0.087*
H8B	−0.2575	0.2953	0.0430	0.087*
H8C	−0.3176	0.1886	−0.0302	0.087*
C9	−0.1841 (4)	0.0559 (5)	0.1006 (3)	0.0659 (14)
H9A	−0.1980	0.1119	0.1442	0.099*
H9B	−0.1224	0.0014	0.1293	0.099*
H9C	−0.2438	−0.0024	0.0726	0.099*
C10	0.3350 (3)	0.2091 (4)	0.2439 (3)	0.0390 (10)
C11	0.4045 (3)	0.0990 (4)	0.2674 (3)	0.0458 (11)
C12	0.4233 (4)	0.0383 (5)	0.3496 (3)	0.0653 (14)
H12	0.4704	−0.0344	0.3670	0.078*
C13	0.3741 (5)	0.0829 (6)	0.4060 (4)	0.0768 (17)
H13	0.3876	0.0402	0.4606	0.092*
C14	0.3050 (4)	0.1908 (6)	0.3816 (3)	0.0670 (15)
H14	0.2713	0.2211	0.4194	0.080*
C15	0.2860 (4)	0.2537 (5)	0.3007 (3)	0.0506 (12)
H15	0.2396	0.3271	0.2842	0.061*
C16	0.4546 (4)	0.0460 (5)	0.2049 (3)	0.0586 (13)
H16A	0.5043	−0.0255	0.2342	0.070*
H16B	0.4004	0.0067	0.1531	0.070*
C17	0.5271 (5)	0.1140 (7)	0.0944 (4)	0.098 (2)
H17A	0.5612	0.1875	0.0758	0.147*
H17B	0.4603	0.0947	0.0483	0.147*
H17C	0.5712	0.0345	0.1054	0.147*
C18	0.6074 (4)	0.1859 (5)	0.2463 (4)	0.0729 (16)
H18A	0.5936	0.2078	0.2993	0.109*
H18B	0.6394	0.2628	0.2289	0.109*
H18C	0.6547	0.1095	0.2578	0.109*
N1	−0.1664 (3)	0.1419 (4)	0.0337 (2)	0.0434 (9)
N2	0.5099 (3)	0.1525 (4)	0.1759 (3)	0.0533 (10)
Se1	0.01400 (3)	0.28240 (4)	0.07642 (3)	0.04106 (14)
Se2	0.16148 (4)	0.42749 (4)	0.10822 (3)	0.05104 (15)
Se3	0.31137 (3)	0.29357 (4)	0.12962 (3)	0.04436 (14)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.032 (2)	0.041 (2)	0.041 (2)	0.0099 (18)	0.0113 (19)	0.0044 (19)
C2	0.032 (2)	0.039 (2)	0.052 (3)	0.0037 (19)	0.013 (2)	0.001 (2)
C3	0.044 (3)	0.066 (3)	0.051 (3)	−0.002 (2)	0.008 (2)	−0.011 (3)
C4	0.064 (4)	0.094 (4)	0.046 (3)	0.009 (3)	0.016 (3)	−0.010 (3)
C5	0.064 (4)	0.082 (4)	0.050 (3)	0.007 (3)	0.029 (3)	0.014 (3)
C6	0.045 (3)	0.047 (3)	0.053 (3)	0.006 (2)	0.021 (2)	0.011 (2)
C7	0.037 (3)	0.044 (3)	0.072 (3)	−0.004 (2)	0.020 (2)	0.001 (2)
C8	0.047 (3)	0.061 (3)	0.072 (3)	0.005 (2)	0.030 (3)	0.005 (3)
C9	0.056 (3)	0.073 (4)	0.070 (4)	−0.008 (3)	0.024 (3)	0.019 (3)
C10	0.034 (2)	0.047 (3)	0.033 (2)	−0.0039 (19)	0.0085 (19)	−0.0054 (19)
C11	0.033 (2)	0.048 (3)	0.050 (3)	0.002 (2)	0.007 (2)	−0.005 (2)
C12	0.064 (3)	0.066 (3)	0.059 (3)	0.017 (3)	0.014 (3)	0.015 (3)
C13	0.074 (4)	0.097 (5)	0.058 (4)	0.011 (3)	0.021 (3)	0.021 (3)
C14	0.062 (3)	0.096 (4)	0.048 (3)	0.010 (3)	0.025 (3)	0.002 (3)
C15	0.042 (3)	0.062 (3)	0.048 (3)	0.009 (2)	0.017 (2)	0.000 (2)
C16	0.041 (3)	0.059 (3)	0.065 (3)	0.008 (2)	0.007 (2)	−0.021 (3)
C17	0.082 (5)	0.147 (6)	0.080 (4)	0.029 (4)	0.047 (4)	−0.006 (4)
C18	0.049 (3)	0.066 (4)	0.091 (4)	−0.003 (3)	0.009 (3)	−0.002 (3)
N1	0.032 (2)	0.049 (2)	0.048 (2)	0.0001 (17)	0.0141 (17)	0.0074 (18)
N2	0.040 (2)	0.066 (3)	0.054 (2)	0.012 (2)	0.0171 (19)	−0.004 (2)
Se1	0.0384 (3)	0.0439 (3)	0.0406 (3)	0.00104 (19)	0.0138 (2)	0.00237 (19)
Se2	0.0422 (3)	0.0376 (3)	0.0630 (3)	−0.0021 (2)	0.0062 (2)	0.0020 (2)
Se3	0.0405 (3)	0.0500 (3)	0.0418 (3)	−0.0069 (2)	0.0140 (2)	−0.0013 (2)

Geometric parameters (Å, º)

C1—C6	1.379 (6)	C10—Se3	1.935 (4)
C1—C2	1.390 (6)	C11—C12	1.388 (6)
C1—Se1	1.946 (4)	C11—C16	1.493 (6)
C2—C3	1.382 (6)	C12—C13	1.374 (7)
C2—C7	1.496 (6)	C12—H12	0.9300
C3—C4	1.373 (7)	C13—C14	1.374 (7)
C3—H3	0.9300	C13—H13	0.9300
C4—C5	1.372 (7)	C14—C15	1.378 (6)
C4—H4	0.9300	C14—H14	0.9300
C5—C6	1.385 (6)	C15—H15	0.9300
C5—H5	0.9300	C16—N2	1.457 (6)
C6—H6	0.9300	C16—H16A	0.9700
C7—N1	1.443 (5)	C16—H16B	0.9700
C7—H7A	0.9700	C17—N2	1.460 (6)
C7—H7B	0.9700	C17—H17A	0.9600
C8—N1	1.448 (5)	C17—H17B	0.9600
C8—H8A	0.9600	C17—H17C	0.9600
C8—H8B	0.9600	C18—N2	1.435 (6)
C8—H8C	0.9600	C18—H18A	0.9600
C9—N1	1.453 (5)	C18—H18B	0.9600
C9—H9A	0.9600	C18—H18C	0.9600
C9—H9B	0.9600	Se1—Se2	2.3545 (6)
C9—H9C	0.9600	Se2—Se3	2.3372 (7)
C10—C15	1.378 (6)	Se1—N1	2.671 (4)
C10—C11	1.394 (6)	Se3—N2	2.873 (4)
C6—C1—C2	120.5 (4)	C12—C13—C14	120.0 (5)
C6—C1—Se1	121.9 (3)	C12—C13—H13	120.0
C2—C1—Se1	117.6 (3)	C14—C13—H13	120.0
C3—C2—C1	118.5 (4)	C13—C14—C15	119.5 (5)
C3—C2—C7	119.7 (4)	C13—C14—H14	120.3
C1—C2—C7	121.8 (4)	C15—C14—H14	120.3
C4—C3—C2	121.4 (5)	C10—C15—C14	120.7 (4)
C4—C3—H3	119.3	C10—C15—H15	119.6
C2—C3—H3	119.3	C14—C15—H15	119.6
C5—C4—C3	119.6 (5)	N2—C16—C11	112.0 (4)
C5—C4—H4	120.2	N2—C16—H16A	109.2
C3—C4—H4	120.2	C11—C16—H16A	109.2
C4—C5—C6	120.4 (5)	N2—C16—H16B	109.2
C4—C5—H5	119.8	C11—C16—H16B	109.2
C6—C5—H5	119.8	H16A—C16—H16B	107.9
C1—C6—C5	119.7 (4)	N2—C17—H17A	109.5
C1—C6—H6	120.2	N2—C17—H17B	109.5
C5—C6—H6	120.2	H17A—C17—H17B	109.5
N1—C7—C2	113.2 (4)	N2—C17—H17C	109.5
N1—C7—H7A	108.9	H17A—C17—H17C	109.5
C2—C7—H7A	108.9	H17B—C17—H17C	109.5
N1—C7—H7B	108.9	N2—C18—H18A	109.5
C2—C7—H7B	108.9	N2—C18—H18B	109.5
H7A—C7—H7B	107.8	H18A—C18—H18B	109.5
N1—C8—H8A	109.5	N2—C18—H18C	109.5
N1—C8—H8B	109.5	H18A—C18—H18C	109.5
H8A—C8—H8B	109.5	H18B—C18—H18C	109.5
N1—C8—H8C	109.5	C7—N1—C8	113.2 (4)
H8A—C8—H8C	109.5	C7—N1—C9	111.5 (4)
H8B—C8—H8C	109.5	C8—N1—C9	111.2 (4)
N1—C9—H9A	109.5	C18—N2—C16	110.2 (4)
N1—C9—H9B	109.5	C18—N2—C17	111.7 (4)
H9A—C9—H9B	109.5	C16—N2—C17	111.5 (4)
N1—C9—H9C	109.5	C1—Se1—Se2	102.65 (12)
H9A—C9—H9C	109.5	Se3—Se2—Se1	108.32 (2)
H9B—C9—H9C	109.5	C10—Se3—Se2	102.73 (12)
C15—C10—C11	120.4 (4)	C1—Se1—N1	76.58 (14)
C15—C10—Se3	122.5 (3)	C10—Se3—N2	74.12 (15)
C11—C10—Se3	117.1 (3)	C7—N1—Se1	93.5 (2)
C12—C11—C10	117.8 (4)	C8—N1—Se1	107.3 (6)
C12—C11—C16	121.2 (4)	C9—N1—Se1	119.2 (3)
C10—C11—C16	120.9 (4)	C16—N2—Se3	83.7 (3)
C13—C12—C11	121.6 (5)	C17—N2—Se3	109.1 (4)
C13—C12—H12	119.2	C18—N2—Se3	127.1 (3)
C11—C12—H12	119.2
C6—C1—C2—C3	0.0 (6)	C16—C11—C12—C13	−177.3 (5)
Se1—C1—C2—C3	−178.4 (3)	C11—C12—C13—C14	−0.5 (9)
C6—C1—C2—C7	176.4 (4)	C12—C13—C14—C15	−0.3 (9)
Se1—C1—C2—C7	−2.0 (5)	C11—C10—C15—C14	0.2 (7)
C1—C2—C3—C4	1.1 (7)	Se3—C10—C15—C14	−179.9 (4)
C7—C2—C3—C4	−175.4 (4)	C13—C14—C15—C10	0.4 (8)
C2—C3—C4—C5	−1.7 (8)	C12—C11—C16—N2	−127.2 (5)
C3—C4—C5—C6	1.3 (8)	C10—C11—C16—N2	54.5 (6)
C2—C1—C6—C5	−0.4 (6)	C2—C7—N1—C8	70.1 (5)
Se1—C1—C6—C5	178.0 (3)	C2—C7—N1—C9	−163.7 (4)
C4—C5—C6—C1	−0.3 (7)	C11—C16—N2—C18	74.8 (5)
C3—C2—C7—N1	−145.3 (4)	C11—C16—N2—C17	−160.6 (4)
C1—C2—C7—N1	38.4 (6)	C6—C1—Se1—Se2	−8.6 (4)
C15—C10—C11—C12	−0.9 (6)	C2—C1—Se1—Se2	169.8 (3)
Se3—C10—C11—C12	179.2 (3)	C1—Se1—Se2—Se3	−81.14 (12)
C15—C10—C11—C16	177.4 (4)	C15—C10—Se3—Se2	−14.0 (4)
Se3—C10—C11—C16	−2.5 (5)	C11—C10—Se3—Se2	165.9 (3)
C10—C11—C12—C13	1.0 (8)	Se1—Se2—Se3—C10	−72.11 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6···Se2	0.93	2.79	3.392 (4)	123
C15—H15···Se2	0.93	2.82	3.404 (5)	122
C7—H7B···C1^i	0.97	2.75	3.713 (4)	170
C7—H7B···C2^i	0.97	2.81	3.732 (4)	158

Symmetry code: (i) −x, −y, −z.