Cation modulated spin state and near room temperature transition within a family of compounds containing the same [FeL₂]²⁻ center

Abstract

Spin-crossover (SCO) active compounds have received much attention due to their potential applications in molecular devices. Herein, a family of solvent-free FeII compounds, formulated as (A)2[FeL2], (H2L = pyridine-2,6-bi-tetrazolate, A...

2,6‐Di(1H‐tetrazol‐1‐yl)pyridine and its cupric chloride complex

“…It should be noted that regioisomer of DTP, namely 2,6di(1H-tetrazol-5-yl)pyridine (7, Scheme 4), has been studied by a number of groups. [36][37][38][39][40] In contrast to DTP, this isomer coordinates metal ions as a chelating tridentate ligand. Such coordination can be stipulated by deprotonation of ligand 7.…”

Trapping an unprecedented octacoordinated iron(ii) complex with neutral bis-tetrazolylpyridyl ligands and solvent molecules

“…16 Strictly related to bpp, 2,6-bis(2 H -tetrazol-5-yl)pyridine (H 2 btp), 18,19 once deprotonated, behaves as anionic nitrogen-donor tridentate ligand, and some examples of heteroleptic 20–22 and homoleptic 23,24 metal complexes are known, together with one unique example with iron( ii ) with the dianionic homoleptic (A) 2 [Fe(btp)] 2 derivatives (A + = ammonium cations). 25 On the other hand, the monoprotic 2-(1 H -pyrazol-1-yl)-6-(2 H -tetrazol-5-yl)pyridine (Hptp) also acts as efficient ligand in promoting SCO in the neutral homoleptic [Fe(ptp) 2 ] species. 26–28…”

Role of Alkylated 2,6‐bis(tetrazol‐5‐yl)pyridyl Ligands and Iron(II) Salts in Selecting Spin Crossover Complexes

“…[19][20][21][22] The related 2,6bis(2H-tetrazol-5-yl)pyridine (H 2 btp) [23,24] tridentate ligand is structurally very similar to bpp derivatives, and it has already been applied in the synthesis of both mer heteroleptic metal complexes with ruthenium(II) [25,26] and platinum(II), [27] and some homoleptic examples with lanthanide ions [28] and 3d metals like cobalt(II), nickel(II), copper(II) and zinc(II), [29] together with one unique example with iron(II) with the dianionic homoleptic (A) 2 [Fe(btp) 2 ] derivatives (A + = ammonium cation). [30] There are also few neutral iron(II) complexes of general formula [Fe(ptp) 2 ] with mixed pyrazolyltetrazolylpyridyl (Hptp) ligands, relevant for their SCO properties. [31,32] In this work we decided to focus our attention on the neutral N2,N2-R 2 btp derivatives (R = Me, tBu), in which the lateral tetrazolyl rings of H 2 btp are alkylated by two methyl or tert-butyl groups on the farther nitrogen atoms (N2) with respect to the central pyridyl ring (to make reading easier, the N2,N2 prefix will be omitted in the following), leading to 2,6bis(2-(methyl)-2H-tetrazol-5-yl)pyridine (Me 2 btp) [26,33] or 2,6bis(2-(tert-butyl)-2H-tetrazol-5-yl)pyridine (tBu 2 btp), respectively.…”

“…Anal. (%) calcd for C30 H 42 Cl 2 FeN 18 O 8 • 1.5H 2 O, 4 a • 1.5H 2 O (936.56): C 38.47, H 4.84, N 26.97. Found: C 38.25, H 4.94, N 26.98.…”