The invention relates to the chemical synthesis of oligonucleotides, e.g., oligoribonucleotides. In another aspect, the invention relates to compounds of formula (II) processes for making these compounds, and the use thereof in the chemical synthesis of oligonucleotides, e.g., oligoribonucleotides. The invention also relates to methods of synthesis of oligomers, including but not limited to oligopeptides, oligosaccharides and oligonucleotides, particularly oligoribonucleotides and also oligodeoxyribonucleotides, in solution systems, and ionic tag linkers for use in methods provided herein.