
pentoosait

 (nii, qoo, kyu) seey2 enna soothravaakyamulla apoorva selenide daathuvaanu pentoosait. ithinu chaaraniratthilulla steel niravum 3 kaadinyamulla karutha varayum undu. ithu 2/meter enna isometric daathuvaanu. 1925ll oru bolivian raiyolaittilaan pentoosait aadyamaayi kandethiyathu. saambathika jiyolajistaaya richard pentosinte (1863-1931) perilaanu ithu ariyappedunnathu.
boleeviyayile pakajakku khaniyil kaanapedunna apoorva daathuvaanu pentoosait. 1925-ll ithu kandethi. extrusive ignius raiyolait paarayile villal sirakalil ithu kaanapettirunnu. athinte gadanayude veekshanakonil ninnu oru cubic space groupulla (bailis, 1989) pairait groupile amgamaayi ithu kanakkaakkappedunnu.
pentoosait mattu daathukkalumaayi vipulamaaya khara laayanikalundakkunnu. udaaharanathinu, olsacherite pibi2 (eso4) (eseo4) polulla niravadhi selenideukalude altermation prakriyayude falamaayirikkaam pentoosait. cheria villalukalude baahya vashathe mathilukal moodunna nannayi roopappetta christalil oolsaacharaitt valare mithamaayi roopappedunnu (hurlbutt, 1969). pentocytumaayi bandhapetta mattoru dhaatu pairettaittaanu. pentoosait polulla uraninite, praadhamika selenium vahikkunna sulfideukalude oru altermation ulppannamaayi ithu sambhavikkunnu. uraninite saambilukalude uparithalathil ooranchu maaswait polulla yuu-pibi ooksaidumaayi sahakarichu pirettaitt puramthottangalayi roopappedunnu (voctain, 1996).
rachana.
athinte gadanaykku moolakangalude mishrithamund, avayil chilath nikkal (nii), chembu (kyu), cobalt (qoo), selenium (seey) thudangiya praadhamika moolakangalaan, avaa parasparam vyathyastha alavil pakarakkaranakkunnu. pentocytil daathukkal nikshepikkappetta prakriyayo paristhithiyo kaaranam kaanapedunna dvitheeya moolakangal silver (eji), merkuri (echji), ledu (pibi) (gorden, 1926) ennivayaanu. eee gadanayude bhaagamaayi kanakkakkappetta ledu, clostalite pbseude paraspara valarcha kaaranam ghadanayil undennu kandethi, ithu oru praadhamika moolakamalla (eayarli, 1950). mattethoru dhatuvineyum pole pentocytil selenium uyarnna alavil adangiyittundu, athinte falamaayi ithu kandethiya aadyathe nikkal selenide daathuvaanennu report cheyyappettu (gorden, 1926).
bhauthika gunangal.
pentoosait oru valia daathuvaanu. ithinu vikiranam, nira, allengil granular ghadana (gorden, 1926) undakam. ithu karutha varayulla mangiya ledu-gray muthal steel-gray vare niram kaanikkunnu. ithinu loha thilakkamundu, durbalamaaya raasabandhamundennu karuthappedunnu, 3 nuu chuttum kuranja kaadinyathode ithu undaakkunnu (eayarli, 1950). ithu echu. enn. oo. 3 allengil keey. sii. enn. ennivayumaayi prathipravartthikkumbol, oru puka thavittuniratthilekku kalangappeduthunnu. ennaal ithu echcl, phcl3, allengil echgcl2 ennivayumaayi prathikarikkukayaanenkil, athu oru pravartthanavum kanikkunnilla (gorden, 1926).
bhoomishaasthraparamaaya sambhavam.
boleeviyayile ororo departmentinte thekkukizhakkayi kolkvechaakkayile pakajakku khaniyilaanu eee dhaatu kaanappedunnath. pentoosait sameepathuninnaan varunnath, ithu riolitil villal sirakalil roopappedunnu. ithu inn-sittuvil kaanapedunnilla, marichu kandethappedaatha sirakalil ninnulla floatil (ayanja parakal) maathram kaanapedunnu, avaa onnukil azhukukayo mukalilulla parvathatthil maranjirikkukayo cheiyunnu (gorden, 1926).
ghadana.
pentocytinu oru cubic space group pii. eiii 3 (bailis, 1989) undu. ithu isotropic paralukal pole pravarthikkunnathaayi kandethi, athil prakasham ellah dishakaliloodeyum ore vegathayil kadannupokunnu, ithu isometric aanennu nigamanam cheyyaan paryaapthamaan (baanisttar, 1937). ithu isometric aayathinal, ellah achuthandukalum ore moolyathinu thulyamaanu. vyathyastha alavukolukal kaaranam eee moolyam 6.001 num 6.017 angstrom (eayarli, 1950) num idayilaanu. pentosaittinte gadanayekkurichu hrasvamaaya vivaranam illaathathinaal, ithinu eathaandu ore pairait subgroup gadanayundu (eayarli, 1950). pairait groupil kaanapedunna bondukalude tharam kovalant aanu, pakshe pentocytilalla. udaaharanathinu, pentosaittinte athe ghadanayum samanamaaya ekopanamundennu karuthappedunna pairait phes 2 nuu, oru phee aattathin chuttum aarr aattangalaal chuttappettirikkunnu, ithu octahedral cordinationaanu. maruvashathu, ezz aattathin chuttum 4 phee attangal oru tetrahedral konfigareshanil undu (jaff, 1988). daathukkalude nirvachikkappedaatha ghadana kaaranam yadhaartha ghadana nirnnayathinte abhaavathil attangal engane pentocytil krameekarichirikkunnu ennathinekkurichu ithu oru dhaarana nalkum.

