Synthetic, structural and luminescence studies of stoichiometric crown ether compounds of Mn(2+) in well-defined coordination environments were undertaken in an effort to understand the origin of emitting crystal defects found in cubic F23 [(K18C6)(4)MnBr(4)][TlBr(4)](2) crystals (Fender, N. S.; et al. Inorg. Chem. 1997, 36, 5539). The new compound [Mn(12C4)(2)][MnBr(4)](2)[N(CH(3))(4)](2) (3) features Mn(2+) ions in eight- and fourfold coordination environments of [Mn(12C4)(2)](2+) and MnBr(4)(2)(-) respectively, while Mn(2+) in [Mn(15C5)(H(2)O)(2)][TlBr(5)] (4) is in the sevenfold coordination polyhedron of [Mn(15C5)(H(2)O)(2)](2+). Crystal data for 3: monoclinic, P2(1)/c (No. 14); a = 14.131(3) Å, b = 12.158(1) Å, c = 14.239(2) Å, beta = 110.37(1) degrees, Z = 2, R1 = 0.039 and wR2 = 0.083. For 3, long-lived emission (77 K decay rate approximately 3 x 10 s(-)(1)) from [Mn(12C4)(2)](2+) (the first for eight-coordinate Mn(2+) in stoichiometric compounds) is observed (lambda(max) approximately 546 nm) along with that of the sensitizing MnBr(4)(2)(-) (lambda(max) approximately 513 nm), which is partially quenched. Emission from the seven-coordinate [Mn(15C5)(H(2)O)(2)](2+) species of 4 and [Mn(15C5)(H(2)O)(2)][MnBr(4)] (the first for seven-coordinate Mn(2+) in stoichiometric compounds) peaks at lambda(max) approximately 592 nm. Unusually intense absorptions attributable to the seven-coordinate species are observed at 317 ((2)T(2)((2)I) <-- (6)A(1)), 342 ((4)T(1)((4)P) <-- (6)A(1)), 406 ((4)E((4)G) <-- (6)A(1)), and 531 ((4)T(1)((4)G) <-- (6)A(1)) nm.

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.

Di­aqua(1,4,7,10,14‐penta­oxa­cyclo­penta­decane)­manganese(II) dibromide, [Mn(C10H20O5)(H2O)2]Br2, prepared in a search for emissive MnII ions in unusual coordination environments, contains the metal ion encircled by the crown ether ligand, with the water mol­ecules in trans axial positions. Hydro­gen bonding between these and the Br− counter‐ions forms chains of cations running approximately parallel to a.