Novel borate supramolecular frameworks constructed from isolated B4/B5 clusters and 1-D B17-based chains

Three new borates [Cu(1,3-dap) 2 (H 2 O) 2 ][Cu(1,3-dap) 2 (B(OH) 3 ) 2 ][B 4 O 5 (OH) 4 ] 2 ( 1, 1,3-dap = 1,3-diaminopropane), [Cu(py) 4 (H 2 O)][B 5 O 6 (OH) 4 ] 2 ·3py·H 2 O ( 2 , py = pyridine) and (HDMF) 2 [NH(CH 3 ) 3 ] 4 [NH 2 (CH 3 ) 2 ] 2 Mg 2 [B 17 O 26 (OH) 4 ][B 17 O 27 (OH) 4 ]·NH 3 ( 3 , DMF = N , N -dimethylformamide) have been synthesized under mild solvothermal conditions and characterized by elemental analysis, IR spectra, diffuse reflectance spectra, thermogravimetric analysis, single-crystal X-ray diffraction and powder X-ray diffraction. 1 and 2 exhibit 3-D supramolecular hydrogen-bonded architectures constructed from isolated oxoboron clusters [B 4 O 5 (OH) 4 ] 2 − and [B 5 O 6 (OH) 4 ] − , respectively. The structure of 3 features two different 1-D chains built by unprecedented [B 17 O 26 (OH) 4 ] 5 − and [B 17 O 27 (OH) 4 ] 7 − clusters, respectively. And the adjacent chains are alternatively linked by H-bonding to form a 3-D supramolecular framework.