Di[(hydroxyalkyl)dimethylammonium] tris[benzene-1,2-diolato(2-)]silicates and their germanium analogs: syntheses, crystal structure analyses, and NMRstudies

Treatment of Si(OMe)(4) with three molar equivalents of 1,2-C6H4(OH)(2) (= 1,2-dihydroxybenzene) and two molar equivalents of HO(CH2)(n)NMe2 (n = 2, 3 ) in acetonitrile at room temperature yields the lambda Si-6-silicates (HO( CH2)(n)NMe2H)(2)(SiL3) (5: n = 2; 6: n = 3; L2- = 1,2-C6H4(O)(2)(2-) (= ben zene-1,2-diolato(2-))). The analogous lambda Ge-6-germanates (HO(CH2)(n)NMe 2H)(2)(GeL3) (7: n = 2; 8: n = 3) were synthesized analogously starting fro m Ge(OMe)(4). Compounds 5.2CH(3)CN and 6-8 were structurally characterized by single-crystal X-ray diffraction. In addition, aqueous solutions of the Si/Ge analogs 5/7 and 6/8 were studied by NMR spectroscopy. The title compo unds may be regarded as model systems for the transport and storage of sili con in biological systems and as tools to investigate biosilification.