Evidence of Conglomerate with Partial Solid Solutions in Ethylammonium Chlocyphos

Aliou Mbodji (1) , Gabin Gbabode (1) , Morgane Sanselme (1) , Yohann Cartigny (1) , Nicolas Couvrat (1) , Michel Leeman (2) , Valérie Dupray (1) , Richard Kellogg (2) , Gérard Coquerel (1, 3)

1 SMS - Sciences et Méthodes Séparatives
2 Syncom B. V.
3 NCU - National Central University [Taiwan]

We established that ethylammonium chlocyphos also belongs to a family of conglomerate-forming systems composed of chlocyphos and alkyl amine. The pure enantiomer and racemic mixture exhibit very close X-ray powder diffraction patterns but with some peak shifts. This led to consider that ethylammonium chlocyphos could crystallize as a conglomerate but with partial solid solutions close to the pure enantiomer. The crystal structures of the pure (S)- and (R)-ethylammonium chlocyphos were solved using single-crystal data. The temperature–composition binary phase diagram between the two enantiomers of ethylammonium chlocyphos system was investigated to determine the limit of the solid solutions. This was confirmed by a Tammann plot related to the eutectic invariant characterizing the melting of the conglomerate. The limit of the composition range of the partial solid solutions was confirmed by X-ray powder diffraction measurements on different enantiomeric compositions.

Domaines: Matériaux; Cristallographie; Chimie inorganique; Chimie organique

Aliou Mbodji, Gabin Gbabode, Morgane Sanselme, Yohann Cartigny, Nicolas Couvrat, et al.. Evidence of Conglomerate with Partial Solid Solutions in Ethylammonium Chlocyphos. Crystal Growth & Design, 2020, 20 (4), pp.2562-2569. ⟨10.1021/acs.cgd.9b01699⟩. ⟨hal-02551765⟩