Why isn the yield for 1 µm scale syntheses five times greater than 0.2 µm scale syntheses?
For 0.2 µm scale, the monomer coupling is done at a 40-50-fold excess. To do so for larger scale syntheses (such as 1.0 µm scale) would be cost-prohibitive. Large-scale syntheses are done at 10-fold mole excess of amidites. However, to increase the yields for these larger scale syntheses, the coupling times are extended to increase coupling efficiencies.
