Several novel triol-ligands functionalized Anderson–Evans type polyoxotungstates, K3Na3[{HOCH2C(CH2O)3}AlO3W6O18], K3Na3[{HOCH2C(CH2O)3}CrO3W6O18], K3Na3[{HOCH2C(CH2O)3}CoO3W6O18], and K3Na3[{H3CC(CH2O)3}CoO3W6O18], were successfully synthesized and characterized, in which some of the central metal ions have never been found in the Anderson-type polyoxotungstates. The single crystal X-ray diffraction analysis indicated that the clusters were on a status, in which only one-side μ3-O was protonated. This indicates that the three-protonated cluster is a common type of Anderson cluster aside zero-protonated (A-type) and six-protonated (B-type), which could be named as the T-type. [ABSTRACT FROM AUTHOR]