Seven-coordinate Mn2+ ions in [Mn(15-crown-5)(H2O)2]2+ as luminescent probes for dynamic supramolecular events†

Abstract

Spectra and temperature dependent decay rates of emission from [Mn(15-crown-5)(H 2 O) 2 ] 2+ ions anchored by a network of O-H…Br…H-O bonds in two-and one-dimensional supramolecular arrays of {[Mn(15-crown-5)(H 2 O) 2 ][TlBr 5 ]} n 1 and {[Mn(15-crown-5)(H 2 O) 2 ]Br 2 } n 2 demonstrate the potential efficacy of manganese(ii) ions as luminescent probes for supramolecular dynamics.

A second polymorph of 1,1,4,4-tetramethylpiperazinium pentabromothallate(III)

“…The structures of just four other compounds containing almost regular trigonal-bipyramidal [TlBr 5 ] 2À anions are reported in the literature (Linden, Nugent et al, 1999;Reid et al, 1999;Linden et al, 2002), although other much more highly distorted [TlBr 5 ] 2À species are known Linden et al, 2002). Of these four compounds, two possess [TlBr 5 ] 2À anions with crystallographic symmetry, namely C 2 symmetry in the N,N H -diethyl-N,N,N H ,N H -tetramethyl-1,2-ethylenediammonium salt (etmeen; Linden et al, 2002)…”

“…[Mn(crown); Reid et al, 1999]. The geometric parameters for each of these anions are included in Table 1 and show that the anion in (Ib) has the least distorted trigonal-bipyramidal geometry of the three structures.…”

Aqua(dipicolinato-κ3O,N,O′)(1H-imidazole-κN3)(1,10-phenanthroline-N,N′)manganese(II)

“…The high-spin d 5 Mn 2+ ion usually favours the formation of the octahedral d 2 sp 3 hybrid orbital instead of the pentagonalbipyramidal coordination involving the d 3 sp 3 hybrid orbital. Several seven-coordinate Mn II complexes are observed with a quinquedentate ligand, such as 15-crown-5 (Reid et al, 1999;Lin et al, 2006), which serves to de®ne a pentagonal plane on the equator and leaves two axial positions open for further coordination to give a regular pentagonal bipyramid. The combination of nearly coplanar phen and pdc ligands [the mean deviation is just 0.095 (1) ] in (I) perfectly functions as a pseudo-quinquedentate ligand, thus giving a new rare example of a pentagonal bipyramid.…”

Synthesis and crystal structure of an infinite one-dimensional chain containing a poly-metallocage of MnII with 4,4′-bis(imidazol-1-ylmethyl)biphenyl

“…time resolved luminescence spectroscopy, make the Mn 2ϩ [ 4 T 1 ( 4 G) → 6 A 1 ] emission attractive as a diagnostic tool for co-ordination characteristics of this metal ion. 23 However, manganese() complexes may emit photoluminescence at low temperature and their luminescent properties at room temperature are rarely reported. 24 In our case the complex in the powdered solid state shows photoluminescence with an emission maximum at 418 nm upon excitation at 359 nm.…”