Tetra-Transition-Metal Substituted Weakley-Type Sandwich Germanotungstates and their Derivatives Decorated by Transition-Metal Complexes

Four classic discrete Weakley-type sandwich germanotungstates, Na 11 H[Co 4 (H 2 O) 2 (α-GeW 9 O 34 ) 2 ]·31H 2 O ( 1 ), [Co(phen) 3 ] 4 H 3 [Co 3 W(H 2 O) 2 (α-GeW 9 O 34 ) 2 ]·4H 2 O ( 2 ), (C 6 N 2 H 18 ) 4 [Co(H 2 O) 6 ]H 2 [Co 4 (H 2 O) 2 (α-GeW 9 O 34 ) 2 ]·5.5H 2 O ( 3 ), Na(H 2 O) 2 (C 6 N 2 H 18 ) 4.75 H 1.5 [Ni 4 (H 2 O) 2 (α-GeW 9 O 34 ) 2 ]·1.5H 2 O ( 4 ), and two novel germanotungstates decorated by transition-metal complexes (C 6 N 2 H 18 ) 3 H 2 [{Co(2,2′-bpy)} 2 Co 4 (H 2 O) 2 (α-GeW 9 O 34 ) 2 ]·4H 2 O ( 5 ) (2,2′-bpy = 2,2′-bipyridine), [Ag(phen) 2 ] 6 H 2 [{Mn(phen)} 2 Mn 4 (H 2 O) 2 (α-GeW 9 O 34 ) 2 ]·3H 2 O ( 6 ) (phen = 1,10-phenanthroline) were synthesized hydrothermally and structurally characterized by elemental analyses, IR spectra, and single-crystal X-ray diffraction structural analysis. Compounds 1 − 4 show the classical tetra-transition-metal substituted Weakley-type sandwich structural frameworks, whereas 5 and 6 represent the new Weakley-type sandwich frameworks decorated by different transition-metal complexes. EPR studies at 110 K and room temperature reveal that the high-spin paramagnetic metal ions (Co 2+, Mn 2+ ) reside in octahedral geometry in 3 and 6, respectively.