4,4-Bis(4-methyl­phenyl­sulfan­yl)-1,1-diphenyl-2-aza­buta-1,3-diene

Rodolphe Kinghat; Hamid Boudiba; Abderrahim Khatyr; Michael Knorr; Marek M Kubicki

doi:10.1107/S1600536807066615

. 2008 Jan 4;64(Pt 2):o370. doi: 10.1107/S1600536807066615

4,4-Bis(4-methylphenylsulfanyl)-1,1-diphenyl-2-azabuta-1,3-diene

Rodolphe Kinghat ^a, Hamid Boudiba ^a, Abderrahim Khatyr ^a, Michael Knorr ^a, Marek M Kubicki ^b,^*

PMCID: PMC2960289 PMID: 21201402

Abstract

In the title compound, C₂₉H₂₅NS₂, both the Cl atoms of the azadiene precursor 4,4-dichloro-1,1-diphenyl-2-azabuta-1,3-diene are replaced by two vicinal S-p-tolyl substituents attached to the terminal C atom of a π-conjugated 2-azabutadiene array. The azadiene chain is planar to within 0.01 Å. One of the phenyl rings seems to be slightly π-conjugated with the azadiene core [dihedral angle 5.1 (2)°].

Related literature

Some related structures of alkoxo- (Jacquot et al., 2000 ▶), cyano- (Jacquot-Rousseau et al., 2002 ▶) and ⁱPrS-substituted (Jacquot-Rousseau et al., 2005 ▶) 4,4-dichloro-1,1-diphenyl-2-azabuta-1,3-dienes (Jacquot et al., 1999 ▶) have been reported. For related literature, see: Tanimoto et al. (1976 ▶); Truce & Boudakian (1956 ▶). graphic file with name e-64-0o370-scheme1.jpg

Experimental

Crystal data

C₂₉H₂₅NS₂
M _r = 451.66
Triclinic,
a = 6.9340 (10) Å
b = 12.3009 (2) Å
c = 14.4247 (3) Å
α = 101.7371 (8)°
β = 98.2522 (7)°
γ = 93.0400 (10)°
V = 1187.90 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 120 (2) K
0.2 × 0.12 × 0.08 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: none
7710 measured reflections
5329 independent reflections
4695 reflections with I > 2σ(I)
R _int = 0.019

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.089
S = 1.04
5329 reflections
317 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.24 e Å⁻³

Data collection: KappaCCD Server Software (Nonius, 1997 ▶); cell refinement: SCALEPACK (Otwinowski & Minor, 1997 ▶); data reduction: DENZO (Otwinowski & Minor, 1997 ▶) and SCALEPACK; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536807066615/gw2031sup1.cif

e-64-0o370-sup1.cif^{(19.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807066615/gw2031Isup2.hkl

e-64-0o370-Isup2.hkl^{(255.6KB, hkl)}

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

Acknowledgments

CNRS is acknowledged for financial support

supplementary crystallographic information

Comment

The investigations of Truce and Boudakian on the reactivity of 1,1-dichloroethylene (1) towards an excess of sodium p-toluenethiolate have shown that this reaction affords exclusively cis-1,2-bis-(p-tolylmercapto) ethane (2). The intermediacy of an alkyne species ArSCCH has been suggested to rationalize this interesting rearrangement reaction which implies some addition–elimination sequences (Truce & Boudakian, 1956). Another research group has later confirmed these findings (Tanimoto et al., 1976) (Fig. 2). In the context of our interest in developing novel π-conjugated dithioether compounds as ligands for coordination chemistry, we have recently reported on the synthesis and crystal structure of [(i-PrS)₂C=C(H)—N=CPh₂] (4a), obtained by reaction of an excess of sodium i-propylthiolate with 4,4-dichloro-1,1-diphenyl-2-azabuta-1,3-diene (3) in DMF as solvent (Jacquot-Rousseau et al., 2005). In the light of the results mentioned above, we were intrigued whether the reaction of (3) (Jacquot et al., 1999) with sodium p-toluenethiolate would lead to [(p-tolylS)₂C=C(H)—N=CPh₂] (4 b) or to an rearranged product bearing the two –S-p-tolyl substituents on two different carbon atoms, similar to the case of olefin (2) (Fig. 3).

The molecular structure of (4 b) is shown in Fig. 1. The transoid conformation of the azabutadiene chain found in precursor (3) and in the S-i-propyl derivative (4a) is also observed in the crystal structure of (4 b). In contrast to compound (2), both the S-p-tolyl substituents are attached to the same C(3) atom.

One may expect that one of the two phenyl groups bound to C(1) makes part of the phenyl/azadiene chain π-conjugation. In fact, a dihedral angle between C10–C15 phenyl plane and that of azadiene chain C1—N—C2—C3 is equal only to 5.1 (2)°. Note that these dihedral angles amount to 28.7 (1)° in precursor (3) and 38.8 (3)° in (4a). An obvious question arises: the reported values of dihedral angles are due to the electronic structures of compounds (3) and (4) or to the packing in the crystals? This problem requires some calculations on the electronic structure of (4 b) and will be separately treated elsewhere.

Experimental

4,4-Dichloro-1,1-diphenyl-2-azabuta-1,3-diene (3) (1.1 mmol) was stirred with an excess of 4-toluenethiolate (8 mmol) in dry DMF (10 ml). The reaction mixture was kept at room temperature for 8 h, then poured into water (100 ml) and extracted with diethyl ether (150 ml). The organic solution was washed three times with water, dried over anhydrous sodium sulfate and evaporated. The crude residue was recristallized from ethanol (75% yield). 1H NMR: δ = 2.30 p.p.m. (s, 3H, Ar—CH3); 2.33 p.p.m. (s, 3H, Ar—CH3);), 6.99–7.02 p.p.m. (m, 8H, phenyl) 7.10 p.p.m. (s, 1H, C=CH), 7.23–7.28 p.p.m. (m, 10H, Ar—H).