Avance III 100 MHz spectrometers with complete proton decoupling. Data is expressed in parts per million (ppm) downfield shifts relative to the internal reference ( δ 77.2 ppm for the central peak of deuterated chloroform) and is reported as position ( δ in ppm). IR spectra were recorded on a Perkin Elmer 688 spectrometer. Mass spectra were obtained on a Shimadzu QP 1000 spectrometer. High resolution mass spectra (HRMS) were recorded using electrospray ionization on a Time of Flight (TOF) mass spectrometer at National Taiwan University.