Boronate ligands (R-B(OH)3-) have recently started to attract attention for the elaboration of coordination polymer networks. Here, three new crystalline structures involving butyl and octylboronate ligands are described: Sr(Bu-B(OH)3)2, Ca(Oct-B(OH)3)2 and Sr(Oct-B(OH)3)2. All were obtained as microcrystalline powders, and their structures were solved using synchrotron powder X-ray diffraction data. IR and multinuclear (13C, 11B, 43Ca, 87Sr and 1H) solid state NMR characterizations were carried out on the materials. Computational models of the novel Sr(Bu-B(OH)3)2 phase and of the previously reported Sr(Ph-B(OH)3)2.H2O structure were then developed. IR O-H stretching modes and NMR parameters were calculated for these models, and discussed in view of the experimental spectra. This work confirms the importance of performing computational studies on boronate phases, to determine the nature of the H-bond network within the materials, and better understand their spectroscopic signatures.