Izakhiwo Zamakhemikhali Zezinto Zokuguquka
Izinto ezishintshayo, ezaziwa nangokuthi izinsimbi ezishintshayo, zihlala ku-d-block yethebula le-periodic futhi zifaka izinto ezivela emaqenjini 3 kuya ku-12. Lezi zinto zibonakala ngokuba khona kwama-d-orbitals agcwele ingxenye, okuthonya kakhulu izakhiwo zawo zamakhemikhali. Indawo eyingqayizivele kanye nokuhlelwa kwama-electron kwezinto ezishintshayo kuzinika izinhlobo eziningi zokuziphatha kwamakhemikhali okuthakazelisayo nokubalulekile. Lesi sihloko sihlola lezi zakhiwo zamakhemikhali ngokuningiliziwe, sihlola izici ezifana nezimo ze-oxidation eziguquguqukayo, ukwakheka okuyinkimbinkimbi, izakhiwo ze-catalytic, kanye nezakhiwo ze-magnetic.
Izimo Zokuxinana Okuguquguqukayo
Esinye sezici eziphawulekayo zezinsimbi zokuguquka yikhono lazo lokubonisa izimo eziningi ze-oxidation. Ngokungafani nezakhi ze-s-block kanye ne-p-block, ezivame ukubonisa izimo ezimbalwa ze-oxidation, izinsimbi zokuguquka zinesimo se-electron esiyinkimbinkimbi esivumela ububanzi obukhulu bezimo ze-oxidation.
Isibonelo, i-manganese ingaba khona ezimweni ze-oxidation ezisukela ku-+2 kuya ku-+7, isimo ngasinye sinezakhiwo zamakhemikhali ezihlukile kanye nokusabela. Lokhu kuphindaphindeka kuvela ngoba umehluko wamandla phakathi kwama-electron e-ns kanye ne-(n-1)d mncane kakhulu, okuvumela kokubili ukuthi kuhileleke ekubophweni.
Leli khono liyisisekelo se-chemistry ehlukahlukene yezinto eziguqukayo. Libenza bakwazi ukuhlanganyela ekuphenduleni kwe-redox futhi bakhe izinhlobo ezahlukene zama-compounds. Ngaphezu kwalokho, izimo eziningi ze-oxidation zibalulekile endimeni yazo njenge-catalysts, njengoba zingasiza ekudalweni nasekuphulweni kwezibopho zamakhemikhali endleleni yokusabela ngokujikeleza ngezimo ezahlukene ze-oxidation.
Ukwakheka Okuyinkimbinkimbi
Izinsimbi zokuguquka zaziwa kakhulu ngekhono lazo lokwakha ama-complexes okuhlanganisa, okuyizinto ezakhiwe ngama-athomu ensimbi aphakathi ahlanganiswe nama-molecule noma ama-ion azungezile, abizwa ngokuthi ama-ligand. Lesi sici sivela ngobukhulu bawo obuncane be-athomu kanye nobuningi be-charge ephezulu, okusebenzisa amandla amakhulu akhangayo kuma-ligand.
Isibonelo, ukwakheka kwe-tetraamminecopper(II) complex, [Cu(NH3)4]2+, kuhilela ama-ion ethusi(II) azungezwe ama-molecule amane e-ammonia. Amandla okwenza ama-complex anjalo awabalulekile nje kuphela ekuqondeni i-transition metal chemistry kodwa futhi anezisetshenziswa ezisebenzayo ezindaweni ezifana ne-catalysis, izinto zikagesi, kanye nemithi.
Ama-ligand angaba ama-molecule angathathi hlangothi njengamanzi (H2O) kanye ne-ammonia (NH3), noma izinhlobo ze-anionic ezifana ne-chloride (Cl-) kanye ne-cyanide (CN-). I-geometry yalezi zinhlanganisela ingahluka, ngokuvamile ibe yi-octahedral, i-tetrahedral, noma i-square planar, kuye ngensimbi kanye nama-ligand ahilelekile. Ukubopha kulezi zinhlanganisela kungachazwa kangcono yi-crystal field theory kanye ne-ligand field theory, echaza isakhiwo se-elekthronikhi, umbala, kanye nezakhiwo zamagnetic zama-compounds okuhlanganisa.
Izakhiwo ze-Catalytic
Izinto ezishintshayo kanye nama-compound azo zivame ukusetshenziswa njengezinto ezithuthukisayo kokubili izinqubo zezimboni kanye nezamakhemikhali. Amakhono azo okuthuthukisa ahlobene kakhulu nezimo zazo ze-oxidation eziguquguqukayo kanye nekhono lokwenza ama-complex.
Kumakhemikhali ezimboni, isibonelo esivamile yinqubo kaHaber, lapho kusetshenziswa khona ama-catalyst ensimbi ukukhiqiza i-ammonia evela ku-nitrogen ne-hydrogen. I-Iron, enezimo zayo eziningi zokuxiliswa kanye nekhono lokwakha ama-intermediate adlulayo, yenza kube lula ukuqhekeka nokwakheka kwezibopho zamakhemikhali ngesikhathi sokusabela.
Ezinhlelweni zezinto eziphilayo, izinsimbi zokuguquka ezifana nensimbi, ithusi, ne-zinc zitholakala kuma-enzyme avuselela ukusabela okubalulekile kwamakhemikhali. Isibonelo, insimbi iyingxenye ebalulekile ye-hemoglobin kanye ne-myoglobin, amaprotheni athutha futhi agcine umoya-mpilo emzimbeni. Indima yokuvuselela yezinsimbi zokuguquka ifinyelela nasezisetshenzisweni zemvelo, lapho zisetshenziswa khona ezinqubweni ezifana neziguquli ze-catalytic ezimotweni ukunciphisa ukukhishwa okuyingozi.
Izakhiwo Zezibuthe
Izinto ezishintshayo zibonisa izinhlobo eziningi zokuziphatha okunamandla ngenxa yokuba khona kwama-d-electron angaxhunywanga. Ama-d-electron angaxhunywanga akhiqiza umzuzu onamandla, okwenza ezinye izinsimbi ezishintshayo kanye nama-compounds azo abe yi-paramagnetic noma i-ferromagnetic.
Izinto ze-paramagnetic, njenge-iron(III) kanye nosawoti we-manganese(II), zinama-electron angahlanganisiwe ahambisana nezinkundla zamagnetic zangaphandle, kodwa alahlekelwa amandla awo okuzibamba lapho insimu isuswa. Izinto ze-Ferromagnetic, njenge-iron, i-cobalt, kanye ne-nickel, zinezizinda zezikhathi zamagnetic ezihambisanayo ezigcina amandla okubamba ngisho nangemva kokuba insimu yangaphandle isusiwe, okwenza zibe ezibalulekile ekwakhiweni kwama-magnets ahlala njalo kanye namadivayisi okugcina.
Ucwaningo lwalezi zakhiwo zikamazibuthe lunemiphumela ewusizo kwezobuchwepheshe obuhlukahlukene, okuhlanganisa i-magnetic resonance imaging (MRI), isitoreji sedatha, kanye nezinzwa ze-elekthronikhi.
Ukwakheka Kwamakhemikhali Anemibala
Ama-compound ensimbi aguqukayo avame ukuba nombala ocacile, okuyisici esivela ekushintsheni kwama-electron e-dd. Lapho ukukhanya kushaya la ma-compound, ama-wavelength athile ayamuncwa ukuze kukhuthazwe ama-electron e-d abe ngamazinga aphezulu amandla, bese ukukhanya okusele kuyadluliselwa noma kuboniswe, okunikeza i-compound umbala wayo.
Imibala ethile incike esimweni se-oxidation yensimbi, uhlobo lwama-ligand, kanye ne-geometry ye-complex. Isibonelo, obomvu obukhazimulayo be-iron(III) thiocyanate, oluhlaza okwesibhakabhaka okujulile kwe-copper(II) sulfate, kanye nohlaza lwe-nickel(II) chloride konke kubonisa umthelela wokuguquka kwe-elekthronikhi ngaphakathi kwama-d-orbitals. Lesi sici sombala sisetshenziswa kakhulu ekuhlaziyweni kwamakhemikhali okwenziwa ukuze kutholakale ukuba khona kwezinsimbi ezithile zokuguquka.
Isiphetho
Izakhiwo zamakhemikhali zezinto eziguqukayo zakhiwe ngokujulile yizimo zazo ezihlukile zama-electron kanye nezimfanelo zesakhiwo. Amandla azo okwamukela izimo eziningi ze-oxidation, ukwakha amakhemikhali ayinkimbinkimbi, ukukhombisa izakhiwo ze-catalytic kanye ne-magnetic, nokukhiqiza amakhemikhali anemibala kuzenza zibe yinto ebaluleke kakhulu emikhakheni eminingi, kusukela ekuqalisweni kwezimboni kanye nesayensi yezinto kuya ezinhlelweni zezinto eziphilayo kanye nezokwelapha. Ukuqonda lezi zakhiwo akugcini nje ngokuhlinzeka ngokuqonda ngezici eziyisisekelo ze-chemistry kodwa futhi kuqhuba ukusungula izinto ezintsha kwezobuchwepheshe kanye nemboni. Njengoba siqhubeka nokuhlola amakhono ezinsimbi eziguqukayo, indima yazo ekuthuthukiseni isayensi kanye nokuthuthukisa izimpilo zethu zansuku zonke isalokhu ibalulekile njengakuqala.
