%0 Journal Article %A Mason, Mark R. %A Perkins, Alisa M. %A Matthews, R. Mark %A Fisher, James D. %A Mashuta, Mark S. %A Vij, Ashwani %D 1998 %T Synthesis and Characterization of Dimeric, Trimeric, and Tetrameric Gallophosphonates and Gallophosphates %U https://acs.figshare.com/articles/journal_contribution/Synthesis_and_Characterization_of_Dimeric_Trimeric_and_Tetrameric_Gallophosphonates_and_Gallophosphates_sup_sup_/3621615 %R 10.1021/ic980132h.s001 %2 https://ndownloader.figshare.com/files/5710257 %K ULM %K t Bu %K THF %K NMR spectroscopy %K t BuGaO 3 PR %K t Bu 3 Ga %K refluxing diglyme %K OH %K H 3 PO 4 %K cuboidal Ga 4 P 4 O 12 cores %K 3 SiNMe 2 %X THF/toluene solutions of phosphonic or phosphoric acids were reacted with tBu3Ga at low temperature to yield the cyclic dimers [tBu2GaO2P(OH)R]2 (R = Ph, Me, tBu, H, OH; 15). Poor crystallinity and variable thermal stabilities of 15 necessitated derivatization with Me3SiNMe2 to yield [tBu2GaO2P(OSiMe3)R]2 (R = Ph, Me, tBu, H, OSiMe3; 610), which were more amenable to purification and characterization. In solution, trans isomers were predominant for 6 and 7 at ambient temperature, whereas the cis isomer of 8 was predominant. NMR spectroscopy demonstrated cis−trans interconversion for 68 and crossover experiments showed interconversion to occur by, or be accompanied with, an intermolecular exchange process. Thermolysis of 3 in refluxing toluene yielded the cluster [(tBuGa)2(tBu2Ga)(O3PtBu)2{O2P(OH)tBu}] (11), which was converted to [(tBuGa)2(tBu2Ga)(O3PtBu)2{O2P(OSiMe3)tBu}] (12) with Me3SiNMe2. Thermolysis of 13 in refluxing diglyme, or solid-state pyrolysis at 250 °C in vacuo, yielded [tBuGaO3PR]4 (R = Ph, tBu, Me; 1315). The gallophosphate [tBuGaO3P(OSiMe3)]4 (16) was similarly obtained by reaction of tBu3Ga with H3PO4 in refluxing diglyme, followed by trimethylsilylation with Me3SiNMe2. Compounds 1316 possess cuboidal Ga4P4O12 cores analogous to double-four-ring secondary building units in the gallophosphates cloverite, gallophosphate-A, and ULM-5. The thermal, hydrolytic, and oxidative stabilities of 1316 are discussed, as are observed intermolecular exchange processes. In addition to characterization of 116 by multinuclear (1H, 13C, 31P) NMR spectroscopy, infrared spectroscopy, mass spectrometry, and elemental analysis, molecular structures for compounds 6, 8, 10, 12, 14, 15, and 16 were determined by X-ray crystallography. %I ACS Publications