A family of inorganic-organic hybrid onedimensional (1-D) chain iron-lanthanide (Ln) heterometal encapsulated tungstotellurates [H2N(CH3)(2)](8)K2Na4 [Ln(2)(Ac)(2) (H2O)(4)Fe-2 (Hpdca)(2) (B-beta-TeW9 O-33)(2)]-[Ln(2)(H2O)(8)Fe-2 (Hpdca)(2) (B-beta-TeW9O33)(2)]center dot 50H(2)O [Ln = Eu3+ (1), Tb3+ (2), Dy3+ (3), Er3+ (4), HAc = acetate acid, H(2)pdca = 2,5-pyridinedicarboxylic acid] were prepared using a facile "one-pot" reaction. The molecular structures of 1-4 consist of an intriguing organic-ligand-connecting Fe-Ln heterometal inserted tetrameric unit [Ln(2)(Ac)(2)(H2O)(4)Fe-2 (Hpdca)(2) (B-beta-TeW9 O-33)(2)] [Ln(2)(H2O)(8)Fe-2-(Hpdca)(2) (B-beta-TeW9O33)(2)](14)(-). Appealingly, the tetrameric unit is composed of two sandwich-type subunits [Ln(2)(Ac)(2)(H2O)(4)Fe-2-(Hpdca)(2) (B-beta-TeW9O33)(2)](8-) and [Ln(2) (H2O)(8)Fe-2-(Hpdca)(2) (B-beta-TeW9O33)(2)](6)(-), in which each sandwich-type subunit can be regarded as a derivative of two Ln-organic complexes substituting two external Fe in ions in the classic Krebs-type [Fe-4(H2O)(10) (beta-TeW9O33)(2)](4-) fragment. Furthermore, adjacent tetrameric units are interconnected into a 1-D chain arrangement by Hpdca - bridges. 1-4 represent the first examples of Fe-Ln heterometal encapsulated tungstotellurates. Comprehensive magnetic measurements of 3 imply the possible single-molecule magnet properties in 3 with an estimated relaxation time tau(0) approximate to 6.06 X 10(-6) s at H-dc = 0 Oe and tau(0) approximate to 6.97 X 10(-5) s at H-dc = 1500 Oe. In addition, the solid-state photoluminescence spectra of 1 and 2 at room temperature exhibit the typical f-f transitions of Ln cations. The Commission International d'Eclairage (CIE) color coordinates of (0.540 24, 0.442 44) for 1 and (0.428 71, 0.428 30) for 2 along with the correlated color temperatures of 1995 and 3278 K, dominant wavelengths of 586 and 578 nm, and color purities of 95.09% and 57.27% for 1 and 2 are obtained.