4 Conclusions
Boron, when surrounded by oxygen, can be either trigonal planar or tetrahedral. An
examination of existing crystal structures of the alkali metal salts reveal a wide
range of possible ways in which these may condense together to form B 2 O,
cyclo-B 3 O 3 , bicyclo-B 4 O 5 , and spirobicyclo-B 5 O 6 units. In some cases, discrete
ions are formed. The structures of these ions have been calculated using
Hartree-Fock, density functional, and Moller Plesset theory with modest basis sets
and the predicted gas-phase geometries are shown to agree quite well with the
crystal structures. In addition, several other structurally-related ions and neutral
molecules have been shown to be minima on the potential energy surface and, while
as yet unobserved, could potentially exist.
Acknowledgements CCP acknowledges ACENet for computational facilities.
References
1. Pye CC (2018) An ab initio study of boric acid, borate, and their interconversion. Prog Theor
Chem Phys 31:143–177
2. Konig H, Hoppe R (1977) Zur Kenntnis von Na 3 BO 3 . Z Anorg Allg Chem 434:225–232 (in
German)
3. Menchetti S, Sabelli C (1982) Structure of hydrated sodium borate Na 2 [BO 2 (OH)]. Acta
Crystallogr B 38:1282–1284
4. Block S, Perloff A (1963) The direct determination of the crystal structure of NaB
(OH) 4 .2H 2 O. Acta Crystallogr 16:1233–1238
5. Csetenyi LJ, Glasser FP, Howie RA (1993) Structure of sodium tetrahydroxyborate. Acta
Crystallogr C 49:1039–1041
6. Andrieux J, Goutaudier C, Laversenne L, Jeanneau E, Miele P (2010) Synthesis,
characterization, and crystal structure of a new trisodium triborate, Na 3 [B 3 O 4 (OH) 4 ]. Inorg
Chem 49:4830–4835
7. Corazza E, Menchetti S, Sabelli C (1975) The crystal structure of Na 3 [B 3 O 5 (OH) 2 ]. Acta
Crystallogr B 31:1993–1997
8. Marezio M, Plettinger HA, Zachariasen WH (1963) The bond lengths in the sodium
metaborate structure. Acta Crystallogr 16:594–595
9. Menchetti S, Sabelli C (1979) A new borate polyanion in the structure of Na 8 [B 12 O 20 (OH) 4 ].
Acta Crystallogr B 35:2488–2493
10. Menchetti S, Sabelli C (1977) The crystal structure of synthetic sodium pentaborate
monohydrate. Acta Crystallogr B 33:3730–3733
11. Menchetti S, Sabelli C, Trosti-Ferroni R (1982) The structure of sodium borate Na 3 [B 5 O 9 ].
H 2 O. Acta Crystallogr B 38:2987–2991
12. Font Tullot JM (1947) El borax como estructura cristalina en cadenas. Estud Geol 7:13–20
(in Spanish)
13. Norimoto N (1956) The crystal structure of borax. Mineral J 2:1–18
14. Levy HA, Lisensky GC (1978) Crystal structures of sodium sulfate decahydrate (Glauber’s
Salt) and sodium tetraborate decahydrate (Borax). Redetermination by neutron diffraction.
Acta Crystallogr B 34:3502–3510
15. Gainsford GJ, Kemmitt T, Higham C (2008) Redetermination of the borax structure from
laboratory X-ray data at 145 K. Acta Crystallogr E 64:i24–i25
138
C. C. Pye
Boron, when surrounded by oxygen, can be either trigonal planar or tetrahedral. An
examination of existing crystal structures of the alkali metal salts reveal a wide
range of possible ways in which these may condense together to form B 2 O,
cyclo-B 3 O 3 , bicyclo-B 4 O 5 , and spirobicyclo-B 5 O 6 units. In some cases, discrete
ions are formed. The structures of these ions have been calculated using
Hartree-Fock, density functional, and Moller Plesset theory with modest basis sets
and the predicted gas-phase geometries are shown to agree quite well with the
crystal structures. In addition, several other structurally-related ions and neutral
molecules have been shown to be minima on the potential energy surface and, while
as yet unobserved, could potentially exist.
Acknowledgements CCP acknowledges ACENet for computational facilities.
References
1. Pye CC (2018) An ab initio study of boric acid, borate, and their interconversion. Prog Theor
Chem Phys 31:143–177
2. Konig H, Hoppe R (1977) Zur Kenntnis von Na 3 BO 3 . Z Anorg Allg Chem 434:225–232 (in
German)
3. Menchetti S, Sabelli C (1982) Structure of hydrated sodium borate Na 2 [BO 2 (OH)]. Acta
Crystallogr B 38:1282–1284
4. Block S, Perloff A (1963) The direct determination of the crystal structure of NaB
(OH) 4 .2H 2 O. Acta Crystallogr 16:1233–1238
5. Csetenyi LJ, Glasser FP, Howie RA (1993) Structure of sodium tetrahydroxyborate. Acta
Crystallogr C 49:1039–1041
6. Andrieux J, Goutaudier C, Laversenne L, Jeanneau E, Miele P (2010) Synthesis,
characterization, and crystal structure of a new trisodium triborate, Na 3 [B 3 O 4 (OH) 4 ]. Inorg
Chem 49:4830–4835
7. Corazza E, Menchetti S, Sabelli C (1975) The crystal structure of Na 3 [B 3 O 5 (OH) 2 ]. Acta
Crystallogr B 31:1993–1997
8. Marezio M, Plettinger HA, Zachariasen WH (1963) The bond lengths in the sodium
metaborate structure. Acta Crystallogr 16:594–595
9. Menchetti S, Sabelli C (1979) A new borate polyanion in the structure of Na 8 [B 12 O 20 (OH) 4 ].
Acta Crystallogr B 35:2488–2493
10. Menchetti S, Sabelli C (1977) The crystal structure of synthetic sodium pentaborate
monohydrate. Acta Crystallogr B 33:3730–3733
11. Menchetti S, Sabelli C, Trosti-Ferroni R (1982) The structure of sodium borate Na 3 [B 5 O 9 ].
H 2 O. Acta Crystallogr B 38:2987–2991
12. Font Tullot JM (1947) El borax como estructura cristalina en cadenas. Estud Geol 7:13–20
(in Spanish)
13. Norimoto N (1956) The crystal structure of borax. Mineral J 2:1–18
14. Levy HA, Lisensky GC (1978) Crystal structures of sodium sulfate decahydrate (Glauber’s
Salt) and sodium tetraborate decahydrate (Borax). Redetermination by neutron diffraction.
Acta Crystallogr B 34:3502–3510
15. Gainsford GJ, Kemmitt T, Higham C (2008) Redetermination of the borax structure from
laboratory X-ray data at 145 K. Acta Crystallogr E 64:i24–i25
138
C. C. Pye