2-[(3,3-Di-methyl-indolin-2-yl-idene)meth-yl]-4-[(3,3-dimethyl-3H-indol-1-ium-2-yl)methyl-idene]-3-oxo-cyclo-but-1-en-1-olate chloro-form disolvate.

In the title squaraine dye solvate, C26H24N2O2·2CHCl3, the dye mol-ecule is essentially planar, except for the methyl groups, having a maximum deviation over the 26-membered delocalized bond system of 0.060 (2) Å. It possesses crystallographic twofold rotational symmetry with the indole ring systems adopting a syn conformation. The mol-ecular structure features intra-molecular N-H⋯O hydrogen bonds enclosing conjoint S7 ring motifs about one of the dioxo-cyclo-butene O atoms, while the two chloro-form solvent mol-ecules are linked to the second O atom through C-H⋯O hydrogen bonds.

Related literature

For the first report of bis­(indole­nine)squaraine dyes with alkyl substituents on the n class="Chemical">N-atom of each of the indole­nine rings, see: Sprenger Von & Ziegenbein (1967 ▶). For background to bis­(indole­nine)squaraine dyes as biomarkers, see: Patsenker et al. (2011 ▶); Sameiro & Gonçalves (2009 ▶). For the structures of some analogues of the parent dye, see: Kobiyashi et al. (1986 ▶); Natsukawa & Nakazumi (1993 ▶); Tong & Peng (1999 ▶); Lynch & Byriel (1999 ▶); Lynch (2002 ▶); Arunkumar et al. (2007 ▶); Matsui et al. (2012 ▶); Lynch et al. (2012 ▶).

Experimental

Crystal data

C26H24N2O2·2CHCl3

M = 635.21

Monoclinic,

a = 20.4270 (11) Å

b = 13.5433 (5) Å

c = 11.4259 (5) Å

β = 109.561 (5)°

V = 2978.5 (3) Å3

Z = 4

Mo Kα radiation

μ = 0.61 mm−1

T = 200 K

0.40 × 0.22 × 0.20 mm

Data collection

Oxford Diffraction Gemini-S CCD-detector diffractometer

Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012 ▶) T min = 0.794, T max = 0.888

10054 measured reflections

2926 independent reflections

2415 reflections with I > 2σ(I)

R int = 0.027

Refinement

R[F 2 > 2σ(F 2)] = 0.044

wR(F 2) = 0.112

S = 1.02

2926 reflections

176 parameters

H-atom parameters constrained

Δρmax = 0.54 e Å−3

Δρmin = −0.50 e Å−3

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATOn class="Chemical">N.

Click here for additional data file.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813010386/su2588sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813010386/su2588Isup2.hkl

Click here for additional data file.

Supplementary material file. DOI: 10.1107/S1600536813010386/su2588Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C26H24N2O2·2CHCl3	F(000) = 1304
Mr = 635.21	Dx = 1.416 Mg m−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2690 reflections
a = 20.4270 (11) Å	θ = 3.3–28.8°
b = 13.5433 (5) Å	µ = 0.61 mm−1
c = 11.4259 (5) Å	T = 200 K
β = 109.561 (5)°	Prism, green
V = 2978.5 (3) Å3	0.40 × 0.22 × 0.20 mm
Z = 4

Oxford Diffraction Gemini-S CCD-detector diffractometer	2926 independent reflections
Radiation source: Enhance (Mo) X-ray source	2415 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
Detector resolution: 16.077 pixels mm-1	θmax = 26.0°, θmin = 3.5°
ω scans	h = −22→25
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012)	k = −16→16
Tmin = 0.794, Tmax = 0.888	l = −13→14
10054 measured reflections

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.112	H-atom parameters constrained
S = 1.02	w = 1/[σ2(Fo2) + (0.047P)2 + 4.0361P] where P = (Fo2 + 2Fc2)/3
2926 reflections	(Δ/σ)max < 0.001
176 parameters	Δρmax = 0.54 e Å−3
0 restraints	Δρmin = −0.50 e Å−3

Experimental. Spectroscopic details of the as synthesized metallic green crystals of the title dye: UV/Vis (CHCl3), recorded on a Nicolet 205 F T—IR spectrometer: λmax (log ε): 665(5.54). IR (KBr, cm-1) recorded on a Unicam UV-4 spectrometer: λmax: 1623 (C—O). Electrospray mass spectra recorded in the the positive (ES+) ion mode: 397.1 [M+H]+, 460.1 [M+Na+MeCN]+, 815.3 [2M+Na]+, 1211.6 [3M+Na]+.

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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.

	x	y	z	Uiso*/Ueq
O1	0.00000	0.35895 (15)	0.75000	0.0420 (8)
O2	0.00000	0.02418 (14)	0.75000	0.0330 (7)
N1	0.08460 (9)	0.01681 (12)	0.60326 (15)	0.0292 (5)
C1	0.00000	0.2681 (2)	0.75000	0.0308 (9)
C2	0.03058 (10)	0.19196 (14)	0.69306 (18)	0.0283 (6)
C3	0.00000	0.1172 (2)	0.75000	0.0273 (8)
C4	0.07197 (11)	0.19354 (15)	0.61835 (19)	0.0300 (6)
C5	0.09788 (10)	0.11037 (14)	0.57941 (18)	0.0272 (6)
C6	0.14808 (11)	0.10979 (15)	0.50618 (19)	0.0298 (6)
C7	0.19200 (12)	−0.05112 (17)	0.4256 (2)	0.0364 (7)
C8	0.18945 (12)	−0.15368 (18)	0.4251 (2)	0.0400 (8)
C9	0.15195 (12)	−0.20386 (17)	0.4872 (2)	0.0390 (7)
C10	0.11502 (12)	−0.15347 (15)	0.55071 (19)	0.0333 (7)
C11	0.11792 (11)	−0.05144 (15)	0.54957 (18)	0.0278 (6)
C12	0.15568 (10)	−0.00001 (15)	0.48861 (18)	0.0293 (6)
C13	0.21729 (12)	0.15545 (17)	0.5872 (2)	0.0397 (7)
C14	0.11833 (13)	0.16552 (17)	0.3829 (2)	0.0400 (8)
Cl1	0.10014 (5)	0.46856 (7)	0.50703 (7)	0.0756 (3)
Cl2	0.09549 (5)	0.60290 (5)	0.70002 (8)	0.0724 (3)
Cl3	0.17949 (4)	0.42725 (6)	0.76203 (7)	0.0650 (3)
C15	0.10219 (14)	0.47904 (18)	0.6610 (2)	0.0444 (8)
H1	0.05820	0.00030	0.64720	0.0350*
H4	0.08300	0.25470	0.59290	0.0360*
H7	0.21760	−0.01770	0.38450	0.0440*
H8	0.21330	−0.18910	0.38230	0.0480*
H9	0.15150	−0.27250	0.48640	0.0470*
H10	0.08950	−0.18680	0.59210	0.0400*
H131	0.23420	0.12070	0.66480	0.0600*
H132	0.21030	0.22370	0.60240	0.0600*
H133	0.25060	0.15050	0.54490	0.0600*
H141	0.15020	0.16100	0.33750	0.0600*
H142	0.11160	0.23360	0.39920	0.0600*
H143	0.07460	0.13680	0.33480	0.0600*
H15	0.06270	0.44250	0.66990	0.0530*

	U11	U22	U33	U12	U13	U23
O1	0.0502 (14)	0.0225 (10)	0.0651 (15)	0.0000	0.0351 (12)	0.0000
O2	0.0396 (12)	0.0231 (10)	0.0439 (12)	0.0000	0.0240 (10)	0.0000
N1	0.0351 (9)	0.0247 (9)	0.0344 (9)	0.0005 (7)	0.0203 (8)	0.0024 (7)
C1	0.0302 (15)	0.0265 (15)	0.0392 (16)	0.0000	0.0161 (13)	0.0000
C2	0.0261 (10)	0.0252 (10)	0.0342 (11)	−0.0004 (8)	0.0111 (9)	0.0009 (8)
C3	0.0260 (14)	0.0265 (15)	0.0304 (14)	0.0000	0.0108 (12)	0.0000
C4	0.0336 (11)	0.0229 (10)	0.0377 (11)	−0.0023 (8)	0.0176 (9)	0.0028 (8)
C5	0.0268 (10)	0.0281 (10)	0.0272 (10)	−0.0018 (8)	0.0099 (8)	0.0017 (8)
C6	0.0315 (11)	0.0308 (11)	0.0310 (10)	−0.0012 (9)	0.0156 (9)	0.0018 (8)
C7	0.0336 (12)	0.0442 (13)	0.0349 (11)	0.0034 (10)	0.0162 (10)	0.0003 (9)
C8	0.0399 (13)	0.0444 (14)	0.0373 (12)	0.0119 (11)	0.0150 (10)	−0.0059 (10)
C9	0.0432 (13)	0.0337 (12)	0.0375 (12)	0.0079 (10)	0.0102 (10)	−0.0026 (9)
C10	0.0392 (12)	0.0288 (11)	0.0325 (11)	−0.0001 (9)	0.0127 (9)	0.0009 (8)
C11	0.0291 (10)	0.0295 (10)	0.0254 (9)	0.0031 (8)	0.0098 (8)	0.0002 (8)
C12	0.0272 (10)	0.0315 (11)	0.0303 (10)	0.0004 (9)	0.0110 (8)	0.0009 (8)
C13	0.0350 (12)	0.0408 (13)	0.0477 (13)	−0.0062 (10)	0.0196 (11)	−0.0029 (10)
C14	0.0524 (15)	0.0354 (12)	0.0366 (12)	0.0007 (11)	0.0206 (11)	0.0076 (9)
Cl1	0.0984 (7)	0.0894 (6)	0.0439 (4)	−0.0101 (5)	0.0303 (4)	−0.0026 (4)
Cl2	0.0981 (6)	0.0384 (4)	0.0764 (5)	−0.0049 (4)	0.0234 (5)	−0.0064 (3)
Cl3	0.0658 (5)	0.0531 (4)	0.0653 (5)	−0.0084 (4)	0.0077 (4)	0.0035 (3)
C15	0.0548 (15)	0.0384 (13)	0.0436 (13)	−0.0135 (12)	0.0214 (12)	−0.0011 (10)

Cl1—C15	1.751 (2)	C7—C8	1.390 (3)
Cl2—C15	1.753 (3)	C8—C9	1.384 (3)
Cl3—C15	1.760 (3)	C9—C10	1.389 (3)
O1—C1	1.230 (3)	C10—C11	1.383 (3)
O2—C3	1.260 (3)	C11—C12	1.387 (3)
N1—C5	1.343 (3)	C4—H4	0.9300
N1—C11	1.405 (3)	C7—H7	0.9300
N1—H1	0.8800	C8—H8	0.9300
C1—C2i	1.466 (3)	C9—H9	0.9300
C1—C2	1.466 (3)	C10—H10	0.9300
C2—C4	1.388 (3)	C13—H133	0.9600
C2—C3	1.453 (3)	C13—H131	0.9600
C4—C5	1.380 (3)	C13—H132	0.9600
C5—C6	1.525 (3)	C14—H141	0.9600
C6—C12	1.516 (3)	C14—H142	0.9600
C6—C13	1.537 (3)	C14—H143	0.9600
C6—C14	1.533 (3)	C15—H15	0.9800
C7—C12	1.380 (3)
C5—N1—C11	111.84 (18)	C6—C12—C7	131.1 (2)
C11—N1—H1	124.00	C6—C12—C11	109.10 (18)
C5—N1—H1	124.00	C2—C4—H4	118.00
C2—C1—C2i	90.59 (19)	C5—C4—H4	118.00
O1—C1—C2i	134.70 (11)	C8—C7—H7	121.00
O1—C1—C2	134.70 (11)	C12—C7—H7	121.00
C1—C2—C3	88.88 (16)	C7—C8—H8	119.00
C1—C2—C4	134.41 (18)	C9—C8—H8	120.00
C3—C2—C4	136.70 (18)	C8—C9—H9	119.00
O2—C3—C2	134.18 (11)	C10—C9—H9	119.00
C2—C3—C2i	91.64 (19)	C9—C10—H10	122.00
O2—C3—C2i	134.18 (11)	C11—C10—H10	122.00
C2—C4—C5	124.33 (19)	C6—C13—H131	109.00
N1—C5—C4	125.4 (2)	C6—C13—H132	110.00
N1—C5—C6	108.97 (17)	C6—C13—H133	109.00
C4—C5—C6	125.59 (18)	H131—C13—H132	110.00
C5—C6—C12	101.26 (16)	H131—C13—H133	110.00
C12—C6—C13	111.12 (18)	H132—C13—H133	109.00
C12—C6—C14	112.84 (17)	C6—C14—H141	109.00
C13—C6—C14	110.92 (18)	C6—C14—H142	109.00
C5—C6—C13	108.62 (17)	C6—C14—H143	109.00
C5—C6—C14	111.66 (19)	H141—C14—H142	109.00
C8—C7—C12	118.5 (2)	H141—C14—H143	109.00
C7—C8—C9	121.0 (2)	H142—C14—H143	110.00
C8—C9—C10	121.2 (2)	Cl1—C15—Cl2	110.82 (13)
C9—C10—C11	117.0 (2)	Cl1—C15—Cl3	109.94 (16)
N1—C11—C12	108.72 (17)	Cl2—C15—Cl3	110.12 (13)
C10—C11—C12	122.6 (2)	Cl1—C15—H15	109.00
N1—C11—C10	128.7 (2)	Cl2—C15—H15	109.00
C7—C12—C11	119.8 (2)	Cl3—C15—H15	109.00
C11—N1—C5—C4	179.2 (2)	C4—C5—C6—C12	−178.6 (2)
C11—N1—C5—C6	−2.7 (2)	C4—C5—C6—C13	64.3 (3)
C5—N1—C11—C10	−177.9 (2)	C4—C5—C6—C14	−58.3 (3)
C5—N1—C11—C12	0.8 (2)	C5—C6—C12—C7	177.2 (2)
O1—C1—C2—C3	180.00 (2)	C5—C6—C12—C11	−2.8 (2)
O1—C1—C2—C4	0.9 (3)	C13—C6—C12—C7	−67.6 (3)
C2i—C1—C2—C3	0.00 (12)	C13—C6—C12—C11	112.4 (2)
C2i—C1—C2—C4	−179.1 (2)	C14—C6—C12—C7	57.7 (3)
C2—C1—C2i—C3	0.02 (16)	C14—C6—C12—C11	−122.3 (2)
C1—C2—C3—O2	180.00 (1)	C12—C7—C8—C9	−0.6 (3)
C1—C2—C3—C2i	0.00 (11)	C8—C7—C12—C6	−179.9 (2)
C4—C2—C3—O2	−0.9 (3)	C8—C7—C12—C11	0.1 (3)
C4—C2—C3—C2i	179.1 (3)	C7—C8—C9—C10	0.8 (4)
C1—C2—C4—C5	176.79 (19)	C8—C9—C10—C11	−0.4 (3)
C3—C2—C4—C5	−1.9 (4)	C9—C10—C11—N1	178.4 (2)
C2—C4—C5—N1	3.0 (3)	C9—C10—C11—C12	−0.1 (3)
C2—C4—C5—C6	−174.8 (2)	N1—C11—C12—C6	1.5 (2)
N1—C5—C6—C12	3.3 (2)	N1—C11—C12—C7	−178.52 (19)
N1—C5—C6—C13	−113.77 (19)	C10—C11—C12—C6	−179.7 (2)
N1—C5—C6—C14	123.59 (19)	C10—C11—C12—C7	0.2 (3)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2	0.88	1.96	2.7835 (18)	156
C15—H15···O1	0.98	2.13	3.075 (3)	161

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O2	0.88	1.96	2.7835 (18)	156
C15—H15⋯O1	0.98	2.13	3.075 (3)	161