Cyanoscorpionates: Synthesis and Crystallographic Characterization of One-Dimensional Cu(I) Coordination Polymers

Abstract

A new cyanoscorpionate ligand, hydrotris(3- t-butyl-4-cyanopyrazolyl)borate (Tp ( t-Bu,4CN )) is reported. Both Tp ( t-Bu,4CN ) and hydrotris(4-cyano-3-phenylpyrazolyl)borate (Tp (Ph,4CN)) form one-dimensional coordination polymers with Cu(I). The polymeric chains align to form channels which, in the case of Tp ( t-Bu,4CN ), can encapsulate solvent molecules, as evidenced by the characterization of one such polymer with encapsulated acetonitrile molecules.

Thallium(I) Complexes of Cyano-Substituted Bispyrazolylborate Ligands

“…The dihedral angle (10), 2.665(10) Å ), and TlBp (t-Bu2) (2.632(12), 2.644(12) Å ) [22]. It is suggested that the increased Tl-N bond lengths are correlated with the electron-withdrawing nature of the cyano substituents, which is also observed for the related Tp Ph,4CN ligand [10,13]. The N-Tl-N bond angle in TlBp Ph,4CN is relatively smaller than those in TlBp 3t-Bu,5Me and TlBp 3t-Bu,5i-Pr , possibly due to the reduced steric demands of the phenyl substituents.…”

“…The synthesis of 3-tert-butyl-4-cyanopyrazole has been reported [13]. A portion of 3-tert-butyl-4-cyanopyrazole (3.00 g, 20.13 mmol) was added to 0.54 g (10.11 mmol) of potassium borohydride in a round bottom flask (100 mL) equipped with a water-cooled condenser.…”

“…In addition to its electron-withdrawing properties, the cyano group is well known for its ability to coordinate to transition metal ions [11]. Thus the cyano-substituted scorpionate ligand has been shown to be able to coordinate to multiple metal ions through both the nitrogen atoms of the pyrazole rings and the cyano substituents, leading to cyanobridged multinuclear complexes and potential coordination polymers [12,13]. Our previous work has involved both cyano-substituted Bp and Tp ligands and corresponding transition metal complexes [9,10,13].…”

“…Thus the cyano-substituted scorpionate ligand has been shown to be able to coordinate to multiple metal ions through both the nitrogen atoms of the pyrazole rings and the cyano substituents, leading to cyanobridged multinuclear complexes and potential coordination polymers [12,13]. Our previous work has involved both cyano-substituted Bp and Tp ligands and corresponding transition metal complexes [9,10,13]. Reported here are the syntheses and structural characterizations of two new cyano-substituted bispyrazolylborate thallium(I) complexes (Scheme 1).…”

Chemistry of the p-block elements with anionic scorpionate ligands

“…Thallium(I) complexes of 3-phenyl-4-cyanopyrazolyl and 3-t-butyl-4-cyanopyrazolyl borates show the familiar trigonal pyramidal structure, but while the phenyl substituted derivative shows some some association into coordination polymers via three cyano-nitrogen atoms interacting with the thallium ion [70], the t-butyl substituted derivative does not exhibit this interaction [71]. This has been rationalised on the basis of the greater steric bulk of the t-butyl group.…”