ISSN:
1432-2234
Keywords:
Boron Polymers
;
Ab initio calculations
;
Band structure calculations
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
Notes:
Abstract Ab initio calculations using a STO-3G basis set have been performed on the polymer systems (HBX) n where X = Be, BH, CH2, NH, and O. Energy band diagrams and accompanying density-of-states plots have been obtained. The highest filled orbital of (HBNH) n and (HBO) n occurs at the X-point and possesses π character while the σ- framework orbital at the X- point is the highest filled level for (HBBe) n , (HBBH) n , and (HBCH2) n . The conduction band for all five species has π symmetry and the band gap of the (HBX) n species increases in the order X = Be 〈 BH 〈 NH 〈 O 〈 CH2. An estimate of the energy of polymerisation of the (HBX) n systems suggests that HBNH is particularly stabilised by polymerisation. The electron distribution in (HBBe) n shows a σ - electron drift towards boron, while in the other four systems the net electron transfer is directed away from boron. There is significant π electron back-donation to boron in (HBO) n and (HBNH) n .
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00550333
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