Title: Classification, terminology
and nomenclature of borophosphates
Durif, Erwin Parthe,
S. Sevov, and Jing-Tai
Completion Date: 2008 - project completed
Throughout the literature a variety of systems for the nomenclature
of borates are used. On the other hand in recent years numerous
compounds were obtained containing boron and phosphorus, which are
called borophosphates. These are built with B-O-B or B-O-P linkages
where structural information and formula are available. Depending
on the formula and structure of the compound, it is observed that
different nomenclatures are used by different people or naming of
the compound is ignored. There are several examples in recent literature
where some difficulties arise in naming borophosphates. The objective
of this project is to provide terminology, classification and naming
of novel borophosphate compounds depending on structure and linking
Borophosphates are the intermediate compounds of the MxOy.B2O3.P2O5
(H2O) system which contain complex anionic structures built
of BO4, BO3 and PO4 groups and their partially
protonated species. Numerous borophosphate compounds have been synthesized
by solid state, solution, hydrothermal and microwave techniques.
The structure of these is based on the linking principles of the
primary building units which should be classified. Borophosphate
anions extend from isolated species, rings, chains, oligomers, layers
and frameworks like silicates.
The main goal of this project is classified as:
1. To investigate some specific structures of boron compounds, containing
phosphates, that have close relation to silicates. Boron in nature
usually occurs as oxy compounds. In borates the structures are determined
by O:B ratio and number of oxygen atoms shared by each BO3
group. In most of the compounds boron is three coordinated, but
there are others where there is a tetrahedral coordination or mixed
coordination. The presence of P in the structural units complicates
the structures. On the other hand there are many hydroxyborates
where OH is bonded to boron as the part of 3 or 4 coordination group.
Searching the literature for different structural units of borophosphates,
may lead to the revision of some formula, their classification and
assigning names to them.
2. The publication of such classification and nomenclature would
enlighten and stimulate the researchers to synthesize new borophosphates.
On the other hand micro- and mesoporous properties of some of these
compounds are very important from the point of designing zeolite
like structures or catalysts.
June 2007 - The task group will meet on 6-7 August 2007 in
China to review the latest progress and formulate a report based
on a recent review by Bastian Ewald, Ya-Xi Huang, and Rüdiger
Kniep titled "Structural Chemistry of Borophosphates, Metalloborophosphates,
and Related Compounds", Z. Anorg. Allg. Chem. 2007,
633, 1517-1540 [doi: 10.1002/zaac.200700232]
August 2008 - During subsequent discussions, the Task Group concluded that since the borophosphates are a very diverse group of compounds with complex structures that span 0-3 dimensional in nature and with a variety of compositions, that it would be extremely difficult to propose a systematic nomenclature covering all possibilities. The Task Force therefore regards its project as complete.
Last update: 16 September 2008