Rearrangement of 5’,6’,7’,8’-tetrahydro-1’H-spiro(cyclohexane-1,2’-quinazolin)-4’(3’H)-one during the Vilsmeier reaction

Treatment of 5’,6’,7’,8’-tetrahydro-1’H-spiro(cyclohexane-1,2’-quinazolin)-4’ (3’H)-one with POCl3 and DMF gives a mixture of 1,2,3,4,5,6,7,8-octahydroacridine-4-carbonitrile and 4,5-diformyl-2,3,6,7,8,10-hexahydroacridine-8a(1H)-carbonitrile, both products resulting from cascade transformations of the primary Vilsmeier intermediates.     

New Luminescent Tetranuclear Lanthanide-Based Silsesquioxane Cage-Like Architectures

The synthesis, structure, magnetic, and luminescence properties investigations of four new cage-like lanthanide-based silsesquioxanes (Cat)₂[(PhSiO_1.5)₈(LnO_1.5)₄(O)(NO_2.5)₆(EtOH)₂(MeCN)₂] (where Cat⁺=Et₄N⁺, PPh₄P⁺ and Ln³⁺=Eu³⁺, Tb³⁺ and (Ph₄P)₄[(PhSiO_1.5)₈(TbO_1.5)₄(O)₂(NO_2.5)₈]⋅10MeCN are reported. They present an unusual prism-like topology of cage architectures and lanthanide-characteristic emission, which makes them the first luminescent cage-like lanthanide silsesquioxanes. One of the Tb³⁺-based cages presents a magnetic spin-flip transition.