Studies Of Charge Distributions In Iron(Ⅱ),Cobalt(Ⅱ), Nickel(Ⅱ) Complexes

According　to　density　functional　theory,　the　electron　density　of　a　system　determines　all　properties　of　the　system.　So　accurate　calculation　of　charge　distributions　in　a　molecular　system　plays　an　important　role　in　explaining　and　predicting　its　structure　and　properties.　Recently,　octahedral　polypyridyl　transition　metal　complexes　and　their　derivatives　have　been　studied　in　fundamental　research　and　applied　research　of　electrochemistry,　photochemistry,　photophysics,　photocatalysis,　biochemistry　and　so　on,　which　gives　rise　to　more　and　more　attention.　Thus　it　seems　very　important　to　accurately　calculate　charge　distributions　of　complexes.　Conventional　ab　initio　methods　are　hard　to　apply　to　large　molecular　systems,　particularly　including　transition　metal　ionic　systems.　Hence,　developing　an　accurate　and　economic　method　to　probe　the　properties　of　large　molecules　is　a　promising　research　area　in　current　theoretical　chemistry.　We　have　built　and　developed　an　atom-bond　electronegativity　equalization　model　(ABEEM)　on　the　basis　of　density　functional　theory　and　electronegativity　equalization　principle.　Through　regression　and　least-squares　optimization,　the　parameters　of　atoms　and　bonds　in　complexes　are　determined.　Using　these　parameters,　charge　distributions　of　iron(II),　cobalt(II),　nickel(II)　complexes　are　calculated.　The　results　of　calculation　may　be　well　relevant　to　those　of　ab　initio　method.　Compared　to　ab　initio　method　it　is　timesaving.　As　a　result,　ABEEM　has　a　widespread　prospect　in　developing　and　applying　to　the　systems　of　transition　metal　complexes.