
kristtal feeld sidhaantham

molecular physixil, kristtal feeld sidhaantham (sii. eph. tii) chuttumulla charge vitharanam (ayoon ayalkkar) ulppaadippikkunna oru staatik electric feeld kaaranam electron oorbittal avasthakalude, saadhaaranayaayi "dii" allengil "eph" oorbittalukalude degenerasikal thakarunnathine vivarikkunnu. transition mettal coordination complexukalude, prathyekichu opttikkal spectrayude (nirangal) vividha spectroscopy vivarikkan eee sidhaantham upayogichittundu. transition mettal complexukalude chila kanthika gunangal, nirangal, jalamsham, spinnel gadanakal ennivaykku sii. eph. tii vijayakaramaayi kaaranamaakunnu, pakshe ithu bandhathe vivarikkan sramikkunnilla. 1930kalil bhauthikashaasthranjaraaya hans bethe joonn hasbrook vaan vleck chernnaanu sii. eph. tii vikasippichath. sii. eph. tii pinneedu molecular oorbittal sidhaanthavumaayi samyojippichu kooduthal yaadhaarthyabodhamullathum sankeernavumaaya ligand feeld sidhaantham (ell. eph. tii) roopappeduthi, ithu transition mettal complexukalile raasa bandha prakriyayekkurichu ulkkaazhcha nalkunnu. bandhathe nannayi vivarikkan inverted ligand feeld sidhaantham (aii. ell. eph. tii) upayogikkendivarunna, aapekshika lohav ligand oorbittal oorjjavum upayogichu undakkiya anumanangal thakarkkunnathiloode sii. eph. tii kooduthal sankeernamaakkaam.
avalokanam.
kristtal feeld sidhaanthamanusarichu, positteev charjju cheytha loha kaatteshanum ligaandinte noonn-bonting electronukalile negatteevu charge thammilulla aakarshanathil ninnaan oru parivartthana lohav ligaandukalum thammilulla prathipravartthanam undaakunnath. ligandukal adangiya pooyint chaarjukalude oru nirayal chuttappettirikkunna anchu degenerate "dii"-oorbittalukalude oorjja mattangal pariganichaanu eee sidhaantham vikasippicheduthath. oru ligand loha ionine sameepikkumbol, ligandil ninnulla electronukal chila "dii"-oorbitalukalumaayi aduthu nilkkukayum mattullavaril ninnu kooduthal akaleyayirikkukayum cheyyum, ithu degeneracy nashtappedutthunnu. dii"-oorbittalukalileyum ligandileyum electronukal samanamaaya chaarjukal thammilulla vikarshanam kaaranam parasparam pinthirippikkunnu. athinaal ligandukalkku aduthulla dii-electronukalkku akaleyullathinekkaal uyarnna oorjjam undaakum, ithu "dii"-oorbittalukal oorjjathil vibhajikkaan kaaranamaakunnu. eee vibhajanathe inipparayunna gadakangal badhikkunnu
loha ioninu chuttum oru octahedroninte konukal roopeekarikkunna aarr ligandukalulla octahedral aanu ettavum saadhaaranamaaya complexes. octahedral samamithiyil "dii"-oorbittalukal oorjja vyathyasamulla rund settukalaayi vibhajikkunnu, δoct (kristtal-feeld vibhajana paaraameettar, saadhaaranayaayi "kwandayude deferentialinte" pathiratti 10 "dii. kyu" kondu soochippikkunnu) avide "dii. ex. aii", "dii. ex. ezz", "dies" oorbittalukal "dii" "isad" 2, "dii" "ex" 2-"vaii" 2 ennivayekkaal oorjjathil kuravaayirikkum, ithinu uyarnna oorjjam undaakum, kaaranam muun group ligandukalil ninnu valare akaleyaan, athinaal kuranja vikarshanam anubhavappedunnu. moonnu thaazhnna oorjja bhramanapathangale mothatthil tii 2 jii ennum rund uyarnna oorjja bhramanapathangale udha. eee labelukal molecular simetri sidhaanthathe adisthaanamaakkiyullathaanu avaa octahedral pooyint grouppinte irreducible praathinidhyangalude perukalaanu, ooo.(ooo akshara pattika kaanuka) saadhaarana bhramanapatha oorjja rekhaachitrangal hye-spin, loow-spin vibhaagathil chuvade nalkiyirikkunnu.
tetrahedral complexukal randaamathe ettavum saadhaaranamaaya tharamaan; ivide naalu ligandukal loha ioninu chuttum oru tetrahedron roopappeduthunnu. oru tetrahedral kristtal feeld vibhajanathil, "dii"-oorbittalukal veendum rund grouppukalaayi vibhajikkappedunnu, δtet enna oorjja vyathyaasathode. thaazhnna oorjja bhramanapathangal "d" z "2 umm" d "x" 2-"y" 2 umm aayirikkum, uyarnna oorjja bhramanapathangal "d" xy "," d "xz", "d" yz "-octahedral kesinu vipareethamaayirikkum. koodaathe, tetrahedral samamithiyile ligand electronukal "dii"-orbittalukalilekku nerittu ooriyantad allaathathinaal, oorjja vibhajanam octahedral kesinekkaal kuravaayirikkum. chathuraakrithiyilulla samatalam, mattu sankeernamaaya jyaamithikal ennivayum sii. eph. tii. yill vivarikkaam.
rando athiladhikamo settu bhramanapathangal thammilulla vidavinte valuppam samuchayathinte ligaandukalum jyamitiyum ulppede niravadhi gadakangale aasrayichirikkunnu. chila ligandukal ellaayppozhum δ enna cheria moolyam uthpaadippikkunnu, mattullava ellaayppozhum valia vibhajanam nalkunnu. ligand feeld sidhaanthathiloode ithinu pinnile kaaranagal vishadeekarikkaam. spectrochemical seerees avaa uthppaadippikkunna vibhajanathinte valuppathaal krameekarichirikkunna ligandukalude anubhavaparamayi uruthirinja oru pattikayaanu (cheria δ muthal valia δ vare; eee patikayum kaanuka):
i − <br − <s2 − <sn − (s-bonded) <cl − <no3 − <n3 − <f − <oh − <c2o42 − <h2o <ncs − (n-bonded) <ch3cn <py <nh3 <en <2,2 '-bipyridine <fen <no2 − <pph3 <cn − <co.
ettavum kooduthal vibhajanam srishtikkunna ligandukal lohathil ninnu ligand back-bondingle earppedaan kazhiyunnavayaanennathu sradhikkendathaanu.
lohathinte ooksideshan avastha uyarnnathum thaazhnnathumaaya oorjja nilakalkkidayil δ-yude valuppathinum kaaranamaakunnu. oru lohathinte ooksideshan avastha vardhikkumbol ntem vyaapthi vardhikkunnu. oru nischitha koottam ligandukalkku oru v3 + complexinekkaal valia δ aayirikkum oru nischitha koottam ligandukalkku, kaaranam charge saandrathayile vyathyasam ligandukale oru v2 + ayoninekkaal v3 + ioninode aduthirikkaan anuvadikkunnu. ligand loha ayon thammilulla cheria dooram valia δ-yilek nayikkunnu, kaaranam ligand loha electronukalum parasparam aduthirikkunnathinaal kooduthal pinthirippikkunnu.
hye-spin, loow-spin.
dii"-oorbittalukalude valia vibhajanathinu kaaranamakunna ligaandukale spectro kemikkal shreniyil ninnulla cn-qoo polulla strong feeld ligandukal ennu vilikkunnu. eee ligandukalulla samuchayangalil, uyarnna oorjja bhramanapathangalilekku electronukal idunnathu prathikoolamaanu. athinaal, aufbou thathwamanusarichu mukalile settukalude janasamkhya aarambhikkunnathin munbu thaazhnna oorjja bhramanapathangal poornnamaayum nirayunnu. ithupolulla samuchayangale "loow spin" ennu vilikkunnu. udaaharanathinu, nambar 2-oru sakthamaaya feeld ligandaanu, ithu oru valia δ uthpaadippikkunnu. 5 "d"-electronukalulla octahedral ayoon [fe (no2) 6] 3 − nuu, "t" 2 "g" levalilulla anchu electronukalumaayum valathuvashath kaanichirikkunna octahedral vibhajana rekhaachithram undaayirikkum. athinaal eee thaazhnna spin avastha hundinte niyamam palikkunnilla.
neremarichu, "d"-oorbittalukalude δ enna cheria vibhajanathinu kaaranamakunna ligaandukale (i−, br− polullava) durbalamaaya feeld ligandukal ennu vilikkunnu. eee saahacharyathil, ore bhramanapathathile rund electronukal parasparam pinthirippikkunnathil, rund electronukale ore kuranja oorjja bhramanapathathil sthaapikkunnathinekkaal uyarnna oorjja bhramanapathangalil sthaapikkunnathu eluppamaanu. athinaal, hundinte niyamathinu anusrithamaayi anchu "dii"-oorbittalukalil oronnilum oru electron idukayum eathenkilum jodiyaakkal sambhavikkunnathin munbu "hye spin" complexukal roopappedukayum cheiyunnu. udaaharanathinu, oru durbalamaaya feeld ligandaaya bii. aarr.-oru cheria δoct uthpaadippikkunnu. athinaal, ayoon [febr6] 3 −, veendum anchu "d"-electronukalulla, anchu bhramanapathangalum ottaykku ulla oru octahedral vibhajana rekhaachithram undaayirikkum.
kuranja spin vibhajanam sambhavikkunnathin, ithinakam ottaykku kaivashamulla bhramanapathathil oru electron sthaapikkunnathinulla oorjja chelavu δ enna oorjja chelavil adhika electronine oru e "g" bhramanapathathil sthaapikkunnathinulla chelavinekkaal kuravaayirikkanam. mukalil soochippichathupole, iii "jii" ennathu soochippikkunnu
"d" "z" "2 umm" "d" "x" "2-" "y" "2 umm octahedral complexukalile t2g-nekkaal uyarnna oorjjamaanu". rund electronukal jodiyakkaan aavashyamaaya oorjjam δ nekkaal kooduthalaanengil, oru electron e "g" yill sthaapikkunnathinulla oorjja chelavu uyarnna spin vibhajanam sambhavikkunnu.
tetrahedral loha samuchayangalkkulla (naalu ligandukal) kristtal feeld vibhajana oorjjathe δtet ennu vilikkunnu, ithu ekadesham 4/9δoct nuu thulyamaanu (ore lohathinum ore ligandukalkkum). athinaal, rund electronukal jodiyakkaan aavashyamaaya oorjjam uyarnna oorjja bhramanapathangalil electronukal sthaapikkunnathinu aavashyamaaya oorjjathekkaal kooduthalaanu. athinaal, tetrahedral complexukal saadhaaranayaayi uyarnna spin aanu.
eee vibhajana rekhaachithrangalude upayogam ekopana samyukthangalude kanthika gunangalekkurichu pravachikkaan sahayikkum. vibhajana rekhaachithrathil jodiyaakkaatha electronukalulla oru samyuktham paragnetic aayirikkum, kaanthikakshethrangalal aakarshikkappedum, athesamayam vibhajana rekhaachithrathil jodiyaakkaatha electronukal illaatha oru samyuktham diamagnetic aayirikkum, athu oru kaanthikakshethram durbalamaayi pinthirippikkum.
sthiratha oorjjam.
oru koottam ligaandukal srishtikkunna kristtal feeldil oru transition mettal ayoon sthaapikkunnathinte falamaayundaakunna sthirathayaanu kristtal feeld stabilisation energy (cfse). dii"-oorbittalukal oru ligand feeldil vibhajikkumbol (mukalil vivarichathupole), avayil chilath anchu "dii"-oorbittalukalum degenerate cheiyunna baarisentar ennariyappedunna oru golaakrithiyilulla feeldumaayi bandhappett mumbathethinekkaal oorjjam kuravaayitheerunnathaanu ithinu kaaranam. udaaharanathinu, oru octahedral kesil, "tii 2 jii" settu baarisentarile bhramanapathangalekkaal oorjjathil kuravaayitheerunnu. ithinte falamaayi, eee bhramanapathangalil eathenkilum electronukal undengil, baarisentarumaayi thaarathamyappeduthumbol ligand feeldil loha ayoon cfse ennariyappedunna alavil kooduthal sthirathayullathaanu. neremarichu, "udha" oorbittalukal (octahedral kesil) baarisentarinekkaal oorjjam kooduthalaanu, athinaal ivayil electronukal idunnathu cfse alavu kuraykkunnu.
oru ashtathala mandalatthile "d"-bhramanapathangalude vibhajanam δoct aanenkil, moonnu "t2g" bhramanapathangal baarisentarumaayi thaarathamyappeduthumbol 2/5 δoct sthiratha kaivarikkukayum "udha" bhramanapathangal 3/5 δoct asthirappeduthukayum cheiyunnu. udaaharanamaayi, pejil kooduthal kaanichirikkunna rund "dii" 5 konfigareshanukal pariganikkuka. loow-spin (topp) udaaharanathinu "t2g" oorbittalukalil anchu electronukal undu, athinaal motham cfse 5 x 2/5 δoct = 2δoct aanu. uyarnna spin (thaazhathe) udaaharanathil, cfse (3 x 2/5 δoct)-(2 x 3/5 δoct) = 0 aanu-eee saahacharyathil, thaazhathe bhramanapathangalile electronukal srishtikkunna sthiratha mukalile bhramanapathangalile electronukalude asthirappeduthunna prabhavam moolam raddaakkappedunnu.
opttikkal propertykal.
niravadhi ekopana samuchayangalude opttikkal gunangal (agiranam, emission spectra ennivayude vishadaamshangal) kristtal feeld sidhaanthathiloode vishadeekarikkaanaakum. ennirunnaalum, palappozhum, loha samuchayangalude aazhathilulla nirangal kooduthal theevramaaya charge-transfer aaveshangalil ninnaan undaakunnath.

