Cu(II)‐promoted cyclization of hydrazonophthalazine to triazolophthalazine; Synthesis and structure diversity of six novel Cu(II)‐triazolophthalazine complexes. (29th May 2019)

• Record Type: Journal Article
• Authors: Soliman, Saied M.; Albering, Jörg H.; El‐Faham, Ayman
• Is Part Of: Applied organometallic chemistry. Volume 33:Number 8(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-05-29
• Subjects: Cu(II)‐triazolophthalazine -- cylization/dehydrogenation -- density functional theory -- Hirshfeld -- hydrazonophthalazine; Organometallic chemistry -- Periodicals; Organometallic compounds -- Periodicals; 547.05
• DOI: 10.1002/aoc.4992
• Languages: English
• ISSNs: 0268-2605

Abstract

Abstract : A novel route for the synthesis of Cu(II)‐triazolophthalazine complexes using the Cu(II)‐promoted cyclization dehydrogenation reactions of hydrazonophthalazines under reflux was presented. Two hydrazonophthalazines were cyclized to the corresponding triazolophthalazine ligands, 3‐pyridin‐2‐yl‐3, 10b‐dihydro‐[1, 2, 4]triazolo[3, 4‐a]phthalazine (TPP ) and 3‐(3, 10b‐dihydro‐[1, 2, 4]triazolo[3, 4‐a]phthalazin‐3‐yl)‐benzoic acid (TP3COOH ), followed by in situ complexation with Cu(II) yielding six novel Cu(II)‐triazolophthalazine complexes depending on the reaction conditions. The molecular and supramolecular structures of the Cu(II)‐triazolophthalazine complexes were discussed. The metal sites have rectangular pyramidal geometry in the [Cu(TPP)Cl2 ]2 ;1 and [Cu(TP3COOEt)Cl2 (H2 O)]2 ;4 dinuclear complexes, distorted square planar in [Cu(TP3COOMe)2 Cl2 ];3, [Cu(TP3COOH)2 Cl2 ];5 and [Cu(TP3COOH)2 Cl2 ]·H2 O;6 and a distorted octahedral in [Cu(TPP)(H2 O)2 (NO3 )2 ];2 . Hirshfeld analysis showed that the O…H, C…H, Cl…H (exceptTP3COOH and2 ), N…H and π‐π stacking interactions are the most important intermolecular contacts. The π‐π stacking interactions are the maximum forTP3COOH and complex6 with net C…C/C…N contacts of 19.4% and 15.4%, respectively. The orbital–orbital interaction energies of the Cu‐N/Cu‐Cl bonds correlated inversely with the corresponding Cu‐N/Cu‐Cl distances, respectively. The charge transfer processes between Cu(II) and ligand groups were also discussed. The charge densities of the Cu(II) centers are reduced to 0.663–0.995 e due to the interactions with the ligand groups coordinating it. Abstract : Cu(II)‐promoted cyclization dehydrogenation reactions of hydrazonophthalazine to triazolophthalazine lead to six novel Cu(II)‐triazolophthalazine complexes. The structure diversity of the studied Cu(II) complexes were elucidated using combined experimental and theoretical techniques.