Using Cu ²⁺ ‐Centered Complexes as Glue: Two New Layered Polyoxotantalates Based on the Interconnection of the {Ta ₆ O ₁₉ } Moiety

Applying the three different solutions [Cu(dien)] 2+ in DMSO/H 2 O, acetonitrile, and [Ta 6 O 19 ] 6‐ /H 2 O in a layering approach, the two new polyxotantalates [Cu(dien)] 5 {(Cu(dien)(H 2 O) 2 )Cu(Ta 6 O 19 ) 2 }·DMSO·32 H 2 O ( I ) and K 2 [(Cu(dien)) 6 {Cu(Ta 6 O 19 ) 2 }]·26H 2 O ( II ) (dien = diethylenetriamine) could be synthesized at room temperature within a short time. In the structures of I and II , a Cu 2+ cation and two [Cu(dien)] 2+ complexes connect two {T 6 O 19 } clusters, forming a {(Cu(dien)) 2 Cu(Ta 6 O 19 ) 2 } unit. In the structure of I , two such units are present, which are crystallographically independent but structurally nearly identical. One of the {(Cu(dien)) 2 Cu(Ta 6 O 19 ) 2 } units is expanded by six Cu 2+ ‐centered complexes, while the second group has TaOCuOTa bridges to eight complexes and forms nearly straight chains. These chains are connected by the former {(Cu(dien)) 2 Cu(Ta 6 O 19 ) 2 } moiety, thus generating layers that contain pores. In the structure of II , the {(Cu(dien)) 2 Cu(Ta 6 O 19 ) 2 } unit is structurally very similar to those of I . The building block is expanded by eight Cu 2+ ‐centered complexes, of which two are terminally coordinated. Each {(Cu(dien)) 2 Cu(Ta 6 O 19 ) 2 } unit is connected to four other units via TaOCuOTa bonds to form a puckered layered structure containing pores. The K + ion is coordinated by nine O atoms in a strongly distorted tricapped trigonal prism.