An orthorhombic polymorph ofN,N′-bis(2-pyridylmethyl)pyrazine-2,3-dicarboxamide

Abstract

Key indicatorsSingle-crystal X-ray study T = 153 K Mean '(C±C) = 0.002 A Ê R factor = 0.032 wR factor = 0.079 Data-to-parameter ratio = 10.1For details of how these key indicators were automatically derived from the article, see

A macrocyclic binuclear copper(II) complex of the ligandN,N′-bis(pyridin-2-ylmethyl)pyrazine-2,3-dicarboxamide

“…Hausmann et al (2003) also reported the structure of a dimeric Cu(BF 4 ) 2 complex with the ligand in a zwitterion form and coordinating in an unusual tridentate(N 3 )±monodentate(O) fashion. A similar complex with Cu(NO 3 ) 2 has been observed by Cati & Stoeckli-Evans (2004b). The structure of a mononuclear cobalt(III) complex with the ligand in a zwitterion form, coordinating in a tridentate fashion, has also been reported (Cati & Stoeckli-Evans, 2004c).…”

“…Cati et al (2004) also described the synthesis of H 2 L and the structure of its triclinic polymorph. The structure of the orthorhombic polymorph of H 2 L has also been described recently (Cati & Stoeckli-Evans, 2004a). Hausmann et al (2003) also reported the structure of a dimeric Cu(BF 4 ) 2 complex with the ligand in a zwitterion form and coordinating in an unusual tridentate(N 3 )±monodentate(O) fashion.…”

Syntheses and crystal structures of a new pyrazine dicarboxamide ligand, N 2,N 3-bis(quinolin-8-yl)pyrazine-2,3-dicarboxamide, and of a copper perchlorate binuclear complex

“…The title ligand, N 2 ,N 3 -bis(quinolin-8-yl)pyrazine-2,3-dicarboxamide (H 2 L1), is very similar to ligand N 2 -[(2,3-dihydropyridin-2-yl)methyl]-N 3 -(pyridin-2-ylmethyl)pyrazine-2,3-dicarboxamide (H 2 L2), for which two polymorphs have been reported Cati & Stoeckli-Evans, 2004). These and other pyrazine-carboxamide ligands were synthesized to explore their coordination behaviour with first-row transition metals and to study the magnetic exchange behaviour of the complexes (Cati, 2002).…”

A neutral macrocyclic binuclear copper(II) complex of the deprotonated form of the ligandN,N′-bis(pyridin-2-ylmethyl)pyrazine-2,3-dicarboxamide

“…Binuclear copper(II) complexes with the ligand coordinating in the bis-tridentate coordination mode (HL À ) have been observed (Cati et al, 2004;Cati & Stoeckli-Evans (2004b). Structures of both copper(II) (Hausmann et al, 2003;Cati et al, 2004) and nickel(II) (Cati et al, 2004) [2 Â 2] grid complexes have been described with the ligand coordinating in a bis-tridentate manner as HL À .…”