An Attempt to Programme the Orientation of Bis(heterocyclic) Azine Heterotopic Sequences around Ag^I, Cu^I and Zn^II Metal Centres

Abstract

Four novel bis(heterocyclic) sequences, which incorporate a 2,2′‐bipyridine system with the 2,2′‐bithiazole, 4,4′‐bithiazole, 2,2′‐bipyrazine or 4,4′‐bipyrimidine units, have been synthesized. In the presence of stoichiometric amounts of CuI, AgI or ZnII cations, fully oriented discrete head‐to‐head (H‐H) or head‐to‐tail (H‐T) species have been observed by NMR and X‐ray crystallography. The orientation of the ligands in the AgI, CuI or Zn II dinuclear complexes during the self‐assembly process appears to be under the control of electronic factors relating to the electronic configuration of the different bis(heterocyclic) sequences. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

An Original Supramolecular Helicate from a Bipyridine–Bipyrazine Ligand Strand and NiII by Self‐Assembly

“…Moreover, as observed previously with the same heterotopic sequence, [13,14] one can notice a selective interstrand orientation which promotes exclusively Ni II coordination between a bipyrazine and a bipyridine unit in the system. From a magnetic point of view, both observation of a simple paramagnetic behaviour and the deviation from this behaviour below 10 K suggest the presence of a weak, antiferromagnetic Ni II -Ni II interaction.…”

“…The metal-metal distance in our Ni complex is 6.96 Å and is much longer than those found in our previous Ag and Cu helicate structures. [13,14] …”

“…The formation of the metal complexes was monitored by UV/ Vis spectrophotometric titration of a solution of the heterotopic bipyridine-bipyrazine ligand 1 [13,14] at room temp. with NiCl 2 (Figure 1) in dry acetonitrile.…”

“…[9][10][11][12] Recently, we have studied the self-assembly of sequential 2-oxapropylene-bridged bipyridine-bidiazine ligand strands with tetracoordinate metal ions into selectively oriented H-H (head-to-head) or H-T (head-to-tail) double-stranded helicates. [13,14] …”

Novel CuI Ethylene Complexes with 6,6′‐Diphenyl‐4,4′‐bipyrimidine Three‐Dimensionally Self‐Assembled by an Intermolecular π‐π Stacking Interaction and a C–H···N Contact

“…It is expected to produce both finite metallamacrocyclic and infinite polymeric compounds with square/ rectangle motifs. However, only a few preliminary reports on coordination polymers of Cu I , [20,21] Ag I [21,22] and Rh III , [23] together with mononuclear complexes of Ni II , [21] Ru II [24][25][26][27][28] and Re I , [29] dinuclear complexes of Ru II [30] and Ag I , [31] and trinuclear complex of Ru II [32] can be found in the literature. In this study, we describe the preparation of new Cu I -C 2 H 4 adducts starting from complexes with 6,6Ј-diphenyl-4,4Ј-bipyrimidine (Ph 2 bpm) as ligand.…”