在七重和八重配位环境中具有Mn(2+)的化学计量化合物的强烈光敏发射。

Intense Photosensitized Emission from Stoichiometric Compounds Featuring Mn(2+) in Seven- and Eightfold Coordination Environments.

作者信息

Reid Howard O. N., Kahwa Ishenkumba A., White Andrew J. P., Williams David J.

机构信息

Chemical Crystallography Laboratory, Chemistry Department, Imperial College of Science, Technology and Medicine, South Kensington, London SW7 2AY, U.K.

出版信息

Inorg Chem. 1998 Jul 27;37(15):3868-3873. doi: 10.1021/ic980035o.

DOI:10.1021/ic980035o

PMID:11670493

Abstract

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) crystals (Fender, N. S.; et al. Inorg. Chem. 1997, 36, 5539). The new compound [Mn(12C4)(2)]MnBr(4)N(CH(3))(4) (3) features Mn(2+) ions in eight- and fourfold coordination environments of Mn(12C4)(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). 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) (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) 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.

摘要

为了理解在立方F23 [(K18C6)(4)MnBr(4)]TlBr(4)晶体中发现的发光晶体缺陷的起源，我们对Mn(2+)在明确配位环境中的化学计量冠醚化合物进行了合成、结构和发光研究（芬德，N.S.等人，《无机化学》，1997年，36卷，5539页）。新化合物[Mn(12C4)(2)]MnBr(4)N(CH(3))(4)（3）的特点是，Mn(2+)离子分别处于Mn(12C4)(2)的八重和四重配位环境以及MnBr(4)(2−)中，而[Mn(15C5)(H(2)O)(2)][TlBr(5)]（4）中的Mn(2+)处于Mn(15C5)(H(2)O)(2)的七重配位多面体中。化合物3的晶体数据：单斜晶系，P2(1)/c（编号14）；a = 14.131(3) Å，b = 12.158(1) Å，c = 14.239(2) Å，β = 110.37(1)°，Z = 2，R1 = 0.039，wR2 = 0.083。对于化合物3，观察到来自Mn(12C4)(2)（化学计量化合物中八配位Mn(2+)的首例）的长寿命发射（77 K时的衰减率约为3×10 s−1）（λmax约为546 nm），同时还有敏化的MnBr(4)(2−)（λmax约为513 nm）的发射，其部分被猝灭。化合物4的七配位Mn(15C5)(H(2)O)(2)物种以及[Mn(15C5)(H(2)O)(2)][MnBr(4)]（化学计量化合物中七配位Mn(2+)的首例）的发射在λmax约为592 nm处达到峰值。在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)）和531（(4)T(1)((4)G) ← (6)A(1)）nm处观察到归因于七配位物种的异常强烈吸收。