Trigonal Planar vs Trigonal Pyramidal
Trigonal planar thiab trigonal pyramidal yog ob lub geometries peb siv los sau npe peb qhov kev npaj ntawm atoms ntawm ib qho molecule hauv qhov chaw. Muaj lwm hom geometry. Linear, khoov, tetrahedral, octahedral yog qee qhov pom geometries. Atoms tau teeb tsa hauv txoj kev no, kom txo qis kev sib cog lus-daim ntawv cog lus repulsion, daim ntawv cog lus-ib khub repulsion, thiab ib leeg khub-ib leeg repulsion. Molecules nrog tib tus naj npawb ntawm atoms thiab electron ib leeg khub zoo li haum rau tib lub geometry. Yog li ntawd, peb tuaj yeem txiav txim siab qhov geometry ntawm ib lub molecule los ntawm kev txiav txim siab qee cov cai. VSEPR txoj kev xav yog ib qho qauv, uas tuaj yeem siv los kwv yees lub molecular geometry ntawm cov molecules, siv tus lej ntawm valence electron khub. Kev sim cov molecular geometry tuaj yeem pom tau siv ntau txoj hauv kev spectroscopic thiab diffraction.
Trigonal Planar
Trigonal planar geometry yog qhia los ntawm cov molecules nrog plaub atoms. Muaj ib lub hauv paus atom, thiab lwm qhov peb lub atoms (peripheral atoms) txuas nrog lub hauv paus atom nyob rau hauv ib txoj kev uas lawv nyob rau hauv lub ces kaum ntawm ib daim duab peb sab. Tsis muaj ib tug khub nyob rau hauv nruab nrab atom; Yog li ntawd, tsuas yog daim ntawv cog lus-daim ntawv cog lus repulsion los ntawm cov pab pawg nyob ib ncig ntawm lub hauv paus atom yog txiav txim siab los txiav txim qhov geometry. Tag nrho cov atoms nyob rau hauv ib lub dav hlau; Yog li ntawd, lub geometry yog hu ua "planar". Lub molecule nrog ib qho zoo tagnrho trigonal planar geometry muaj lub kaum sab xis ntawm 120 o nruab nrab ntawm lub peripheral atoms. Xws li cov molecules yuav muaj tib hom peripheral atoms. Boron trifluoride (BF3) yog ib qho piv txwv rau ib qho zoo tagnrho molecule uas muaj qhov geometry. Tsis tas li ntawd, tuaj yeem muaj cov molecules nrog ntau hom peripheral atoms. Piv txwv li, COCl2 tuaj yeem noj. Nyob rau hauv xws li ib tug molecule, lub kaum sab xis yuav txawv me ntsis ntawm qhov zoo tagnrho tus nqi nyob ntawm seb hom atoms. Ntxiv mus, carbonate, sulfates yog ob inorganic anions uas qhia qhov geometry. Lwm yam tshaj li atoms nyob rau hauv peripheral qhov chaw, muaj peev xwm muaj ligands los yog lwm yam complex pawg nyob ib ncig ntawm lub hauv paus atom nyob rau hauv ib tug trigonal planar geometry. C(NH2)3+ yog ib qho piv txwv ntawm xws li kev sib xyaw, qhov twg peb NH 2 pawg raug khi rau hauv nruab nrab carbon atom.
Trigonal Pyramidal
Trigonal pyramidal geometry kuj pom los ntawm cov molecules muaj plaub atoms lossis ligands. Central atom yuav nyob rau ntawm lub apex thiab peb lwm atoms los yog ligands yuav nyob rau hauv ib lub hauv paus, qhov twg lawv nyob rau hauv peb lub ces kaum ntawm ib daim duab peb sab. Muaj ib khub ntawm electrons nyob hauv nruab nrab atom. Nws yog ib qho yooj yim to taub lub trigonal planar geometry los ntawm kev pom nws ua tetrahedral geometry. Hauv qhov no, tag nrho peb daim ntawv cog lus thiab tus khub ib leeg yog nyob rau hauv plaub axis ntawm tetrahedral zoo li. Yog li thaum txoj hauj lwm ntawm tus khub ib leeg tsis quav ntsej, cov nyiaj tshuav ntxiv ua rau trigonal pyramidal geometry. Txij li thaum tus khub ib leeg- daim ntawv cog lus repulsion ntau dua li daim ntawv cog lus - daim ntawv cog lus repulsion, qhov sib txuas peb lub atoms thiab ib leeg yuav nyob deb li qhov ua tau. Lub kaum sab xis ntawm cov atoms yuav tsawg dua lub kaum sab xis ntawm tetrahedron (109 o). Feem ntau lub kaum sab xis nyob rau hauv lub pyramid trigonal yog hais txog 107 oAmmonia, chlorate ion, thiab sulfite ion yog qee qhov piv txwv uas qhia qhov geometry.
Qhov txawv ntawm Trigonal Planar thiab Trigonal Pyramidal yog dab tsi?
• Hauv trigonal planar, tsis muaj ib khub electrons nyob hauv nruab nrab atom. Tab sis nyob rau hauv trigonal pyramidal muaj ib leeg ib khub ntawm lub hauv paus atom.
• Lub kaum sab xis ntawm lub phiaj xwm trigonal yog nyob ib ncig ntawm 120o, thiab hauv trigonal pyramidal, nws yog nyob ib ncig ntawm 107o.
• Hauv trigonal planar, tag nrho cov atoms nyob hauv ib lub dav hlau tab sis, hauv trigonal pyramidal lawv tsis nyob hauv ib lub dav hlau.
• Nyob rau hauv trigonal planar, tsuas muaj daim ntawv cog lus-daim ntawv cog lus repulsion. Tab sis nyob rau hauv trigonal pyramidal muaj daim ntawv cog lus-daim ntawv cog lus thiab daim ntawv cog lus- ib leeg khub repulsion.
