Co-crystallising two functional complex molecules in a terpyridine embrace lattice

Iron(ii) and cobalt(ii) complexes of tris-azinyl analogues of 2,2′:6′,2′′-terpyridine

“…1 and 2 ), which all adopt the layered "terpyridine embrace" lattice type 32 in the space group Cc. 26,29,33 However, 1a·MeNO 2 and 2b both adopt different 50 versions of the terpyridine embrace structure, in P2 1 /c and P 4 2 1 c respectively. The other two structures adopt different crystal packing modes, with no intermolecular - interactions between the complex cations.…”

Doping ruthenium complexes into a molecular spin-crossover material

“…None-the-less, it is clear that the host compound and the two dopant complexes retain their integrity during the 1-2 days required for the synthesis of the solid solutions described below. Following our previous protocol [15,17,18] [15][16][17][18], x was consistently higher by microanalysis than expected from the mole ratios of the complexes in the crystallization solutions. That may reflect a higher solubility of the ruthenium dopant compared to the iron complex, which therefore crystallizes preferentially.…”

“…Our initial work has produced homogeneous solid solutions of [Fe(bpp) 2 ][BF 4 ] 2 (bpp = 2,6-di{pyrazol-1-yl}pyridine) [14] with [M(terpy) 2 ][BF 4 ] 2 complexes (terpy = 2,2':6',2"-terpyridine; M = Ru [15,16], Co [16,17] or Cu [18]; Scheme 1). This work afforded solid materials exhibiting both spin-crossover with fluorescence, albeit at different temperatures [15], and the first observation of allosteric switching of two different spin-crossover centers in the same material [17] 2 dopants are particularly suited to each other because they have the same molecular symmetry and charge balance; their cations are similar (but not identical) in size and shape; and, although they are not isostructural, the two compounds adopt the same type of "terpyridine embrace" crystal packing motif [15]. Scheme 1.…”

Spin-crossover and the LIESST effect in [Fe Co1‒(bpp)2][BF4]2 (1.00 ≤x≤ 0.77). Comparison with bifunctional solid solutions of iron and cobalt spin-crossover centers

“…The method exploits the fact that spin-crossover complexes of the [Fe(bpp) 2 ]X 2 type (bpp = 2,6-di{pyrazol-1-yl}pyridine; X = BF 4 -or ClO 4 -) often adopt the "terpyridine embrace" crystal packing [30], which is also exhibited by functional complexes of other tris-heterocyclic ligands such as [M(terpy) 2 ] 2+ (terpy = 2,2':6',2''-terpyridine) [31]. Although they are not perfectly isostructural as pure compounds, [Fe(bpp) 2 4 ] 2 materials that show both spin-crossover and fluorescence (M = Ru) [25,26], or exhibit allosteric switching of two different spin-crossover centers in the same material (M = Co) [26,27].…”

“…Six years ago we introduced a new approach towards this goal by doping functional complex cations into a spin-crossover host lattice [25][26][27][28][29]. The method exploits the fact that spin-crossover complexes of the [Fe(bpp) 2 ]X 2 type (bpp = 2,6-di{pyrazol-1-yl}pyridine; X = BF 4 -or ClO 4 -) often adopt the "terpyridine embrace" crystal packing [30], which is also exhibited by functional complexes of other tris-heterocyclic ligands such as [M(terpy) 2 ] 2+ (terpy = 2,2':6',2''-terpyridine) [31].…”