Saddle-shaped macrocycle distortion and symmetry decrease in cobalt (II) meso-tetraphenylporphyrin: Structure of a dichloromethane solvate and DFT calculations Cristiane Cabral de Melo a , Wania da Conceição Moreira a , Tássia Joi Martins a , Márcia Regina Cordeiro b , Javier Ellena c , Freddy Fernandes Guimarães d , Felipe Terra Martins d,⇑ a Departamento de Química, Universidade Federal de São Carlos, São Carlos, SP 13565-905, Brazil b Instituto de Ciências Exatas, Universidade Federal de Alfenas, Alfenas, MG 37130-000, Brazil c Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP 13560-970, Brazil d Instituto de Química, Universidade Federal de Goiás, Goiânia, GO 74001-970, Brazil highlights  Synthesis and crystal structure of new dichloromethane solvate form of cobalt (II) meso-tetraphenylporphyrin (CoTPP).  First observation of a CoTPP structure with a saddle-shaped conformation.  Potential energy surface calculation of torsion angle describing phenyl conformation in both non-solvated and solvate forms.  Saddle-shaped macrocycle distortion dependence of the unlike phenyl conformation decreasing symmetry in the solvate. graphical abstract article info Article history: Received 9 May 2014 Received in revised form 1 August 2014 Accepted 1 August 2014 Available online 12 August 2014 Keywords: Cobalt (II) meso-tetraphenylporphyrin CoTPP Saddle-shaped macrocycle distortion Solvate PES calculation abstract Many studies about porphyrins have emerged in recent years, including studies using porphyrins as building blocks for supramolecular assemblies. Understanding new solid state forms of porphyrins and the elucidation of their structures can have remarkable benefits for nanoscience and synthetic biology. In this study, a new pseudopolymorph of cobalt (II) meso-tetraphenylporphyrin, (CoTPP), was synthesized in a known one-pot reaction, rather than using many-step conventional methods, was isolated and was characterized for the first time by low-temperature single crystal X-ray diffraction. It is a nonstoichiomet- ric solvate assembled into dichloromethane channels. The most striking feature of this structure is the conformation adopted by the porphyrin macrocycle. In contrast to the non-solvated form of CoTPP that exhibits a ruffled core distortion and crystallizes in the tetragonal space group I-42d, this solvated form has been crystallized in the triclinic space group Pı¯ and shows a distinct saddle-shaped macrocycle dis- tortion. In the triclinic form, the conformation of one of the four phenyl rings is remarkably different from the others. A potential energy surface scan of the torsional angles around the bonds between this phenyl moiety and the macrocycle of CoTPP in both the non-solvated and the solvate forms demonstrates that the saddle-shaped macrocycle distortion depends on the unusual phenyl conformation. The distortion is responsible for the symmetry decrease in the channel solvate form, causing a loss of the 4-fold rotoin- version axis observed in the non-solvated tetragonal phase, which has identical phenyl conformations. Ó 2014 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.molstruc.2014.08.001 0022-2860/Ó 2014 Elsevier B.V. All rights reserved. ⇑ Corresponding author. E-mail address: felipe@ufg.br (F.T. Martins). Journal of Molecular Structure 1076 (2014) 468–474 Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: www.elsevier.com/locate/molstruc