The hydrogenphosphate complex of (1,5-cyclooctadiene)iridium(I), {[Bu4N][(1,5-COD)Ir center dot HPO4]}(n): Synthesis, spectroscopic characterization, and ES-MS of a new, preferred precursor to HPO42- and Bu4N+ stabilized Ir(0)(n) nanoclusters

2004-02-09
Özkar, Saim
Finke, RG
The synthesis and characterization of a previously unknown, rare organometallic-phosphate complex, {[Bu4N][(1,5-COD)Ir.HPO4]}(n) (1), is described. Characterization of 1 was accomplished by elemental analysis, electrospray mass spectrometry (ES-MS), and H-1 and C-13 NMR which established the symmetry of the product as at least C-2 or C-5. The ES-MS reveals an interesting, Ir(I) to Ir(III) oxidative process with intense peaks displaying the Ir-191/Ir-193 isotopic distribution patterns expected for the fragments [(1,5-COD)Ir-III(HPO4)(2)](-), [(C8H11)(2)(Ir-III)(2)(PO4)(HPO4)(H2O)](-), and [(C8H11)(2)(Ir-III)(2)(PO4)(HPO4)(H2O)(2)](-). These fragments, in turn, provide evidence for a structure with two HPO42- groups attached to a single Ir, for example ring structures (of at least such C-2 or C-5 symmetry) such as {[Bu4N][(1,5-COD)Ir.HPO4]}(2). Complex 1 is significant since it is known to be the preferred, compositionally precise precursor to the prototype example of a recently discovered class of novel, HPO42- and Bu4N+ stabilized nanoclusters, (Bu4N)(2n)(2n+)[Ir(0)(n).(HPO4)(n)](2n-). Such nanoclusters are being extended, via their analogous hydrogenphosphate-organometallic precursors (1,5-COD)M+ (or 2+)/HPO42- (M = Rh(I), Ru(II), Pt(II)) to their corresponding, catalytically active [M(0)(n).(HPO4)(n)](2n-) nanoclusters.

Citation Formats
S. Özkar and R. Finke, “The hydrogenphosphate complex of (1,5-cyclooctadiene)iridium(I), {[Bu4N][(1,5-COD)Ir center dot HPO4]}(n): Synthesis, spectroscopic characterization, and ES-MS of a new, preferred precursor to HPO42- and Bu4N+ stabilized Ir(0)(n) nanoclusters,” JOURNAL OF ORGANOMETALLIC CHEMISTRY, vol. 689, no. 3, pp. 493–501, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46688.