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A trimeric tri-Tb3+-including antimonotungstate (AMT) hybrid Na17{(WO4)[Tb(H2O)(Ac)(B-α-SbW9O31(OH)2)]3}·50H2O (Tb3W28) was successfully synthesized, in which the capped tetrahedral {WO4} group plays a significant template role in directing the aggregation of three [B-α-SbW9O33]9− fragments and three Tb3+ ions. Eu3+/Tb3+/Dy3+/Gd3+-codoped AMT materials based on Tb3W28 were firstly prepared and their luminescence properties were investigated. The red emitter Eu3+, yellow emitter Dy3+, and nonluminous Gd3+ ions were codoped into Tb3W28 to substitute Tb3+ ions for investigating the energy transfer (ET) mechanism among Eu3+, Tb3+, and Dy3+ ions. Upon the 6H15/2 → 4I13/2 excitation at 389 nm of the Dy3+ ion, the ET1 mechanism (Dy3+ → Tb3+) was confirmed as a non-radiative dipole–dipole interaction. Under the 7F6 → 5L10 excitation at 370 nm of the Tb3+ ion, the ET2 mechanism (Tb3+ → Eu3+) was identified as a non-radiative quadrupole–quadrupole interaction. Under excitation at 389 nm, the two-step successive Dy3+ → Tb3+ → Eu3+ ET3 process was proved in Dy1.2Tb3zEu0.03Gd1.77−3zW28. Through changing the excitation wavelengths, the emission color of Dy1.2Tb1.2Eu0.03Gd0.57W28 can vary from blue to yellow, in which a near-white-light emission case was observed upon excitation at 378 nm. This work not only provides a systematic ET mechanism study of hetero-Ln-codoped AMTs, but also offers some useful guidance for designing novel performance-oriented Ln-codoped polyoxometalate-based materials. [ABSTRACT FROM AUTHOR]

A tetrahedral {HPO 3 } and {WO 4 } group simultaneously directing acetate-decorated tri-Tb(III)-containing antimonotungstate was prepared and characterized. • Inorganic-organic hybrid trimer antimonotungstate. • Tetrahedral {HPO 3 } and tetrahedral {WO 4 } group directing tri-Tb(III)-containing antimonotungstate. • Photoluminescence properties. A tetrahedral {HPO 3 } and {WO 4 } group simultaneously directing tri-Tb(III)-containing antimonotungstate (AT) K 3 Na 21 H[Tb 3 (Ac) 3 (HPO 3)(WO 4)][B- α -SbW 9 O 33 ] 3 ·36H 2 O (1) has been triumphantly isolated by the aqueous reaction of Na 9 [B- α -SbW 9 O 33 ]·19·.5H 2 O, Na 2 WO 4 ·2H 2 O, H 3 PO 3 and Tb(NO 3) 3 ·6H 2 O. Notably, tetrahedral {HPO 3 } and {WO 4 } groups may play the template-directing function in the formation of polyoxoanion of 1. Under the excitation at 380 nm, the emission spectrum and the decay lifetime curve of 1 have been measured. Upon the O → W LMCT excitation at 260 nm, energy transfer from AT fragments to Tb3+ ions has occurred because Tb3+ ions can absorb energy from the O → W LMCT emission of AT fragments. By switching the excitation wavelength from 250 to 390 nm, it's available to tune the emission color of 1 from blue to green. [ABSTRACT FROM AUTHOR]

A terbium-antimony-oxo-cluster bridging antimonotungstate comprising divacant and tetravacant Keggin segments was prepared and characterized. • Tetramer bridging antimonotungstate. • Terbium-antimony-oxo-cluster bridging antimonotungstate. • Photoluminescence properties. • Energy transfer. A terbium-antimony-oxo-cluster bridging antimonotungstate (AT) [H 2 N(CH 3) 2 ] 8 Na 6 H 8 {[Tb 4 (H 2 O) 6 Sb 6 O 4 ](SbW 10 O 37) 2 (B- α -SbW 8 O 31) 2 }·24H 2 O (1) was successfully prepared by reaction of Na 9 [B- α -SbW 9 O 33 ]·19·.5H 2 O, SbCl 3 , Tb(NO 3) 3 ·6H 2 O and dimethylamine hydrochloride (DMA·HCl) in acidic aqueous solution. Its tetramer polyanion consists of two divacant [SbW 10 O 37 ]11− and two tetravacant [B- α -SbW 8 O 31 ]11− fragments linked by two [Tb 2 (H 2 O) 3 Sb 3 O 2 ]11+ clusters. The photoluminescence emission spectra and lifetime decay curves of 1 are collected respectively under the most f−f excitation at 368 nm and O → W LMCT excitation at 268 nm. The sensitization of AT fragments can enhance the f−f transition emission intensity of Tb3+ ions and prolong the lifetime of Tb3+ ions. The time-resolved emission spectrum of 1 reveals that the decay rate of characteristic emission peaks of Tb3+ ions has been inhibited because of the sensitization effect of AT fragments to Tb3+ ions. The emission spectra under different excitation wavelengths indicate that the excitation at 268 nm from O → W LMCT is the most suitable excitation and can obtain the strongest emission spectrum of 1. Their corresponding CIE coordinates demonstrate that the emission colors of 1 can be tuned by changing different excitation wavelengths. [ABSTRACT FROM AUTHOR]