Answer to Question #22157 in Organic Chemistry for naeim vhora
"between NH3 and PH3 ,NH3 is a better electron donor because the lone pair of electrons occupies sp3 orbital and is more directional." explain the sentence in simple terms.
An electron donor is a chemical entity that donates electrons to another compound. It is a reducing agent that, by virtue of its donating electrons, is itself oxidized in the process.Typical reducing agents undergo permanent chemical alteration through covalent or ionic reaction chemistry. This results in the complete and irreversible transfer of one or more electrons. In many chemical circumstances, however, the transfer of electronic charge to an electron acceptor may be only fractional, meaning an electron is not completely transferred, but results in an electron resonance between the donor and acceptor. This leads to the formation of charge transfer complexes in which the components largely retain their chemical identities.More directional means that pair of the electrons has more likely to the formation of charge transfer complexes.