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HAL Id: jpa-00227246

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Submitted on 1 Jan 1987

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CHEMICAL EFFECTS IN MULTIELECTRON PROCESSES IN THE FLUORIDE ANION

R. Hessabi, D. Urch

To cite this version:

R. Hessabi, D. Urch. CHEMICAL EFFECTS IN MULTIELECTRON PROCESSES IN THE FLUORIDE ANION. Journal de Physique Colloques, 1987, 48 (C9), pp.C2-777-C2-780.

�10.1051/jphyscol:19879136�. �jpa-00227246�

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Colloque C9, supplkment n012, Tome 48, dkcembre 1987

CHEMICAL EFFECTS IN MULTIELECTRON PROCESSES IN T H E FLUORIDE ANION

R. HESSABI and D. URCH

Chemistry Department, Queen Mary College, Mile End Road.

GB-London El 4NS, Great-Britain

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a n d HF w h i c h h a v e 1.os.t z e r o , cane o r - tzwn e l e r : . t r o n s . 9.6 t h e s e l e ? v e l s a r e j o i r ' i e d i t i s t h e ? ? p o s s i b l e t o e s t i m a t e t h e e n e r g i e s o f t h e s e sta.l-.c$s i t ? 91-1 e l e c t r o s . t a t i c : f i e l d , s i r c h a s w o u l d h e f o u n d i n a c r y s t a : l .

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1. Introduction

I n c h e m i c a l c o m b i n a t j . o r ? f l u o r i n e w i l l . a t t e n ~ p t t o ac:hi.eve a n e o n - - l i k e c o n + i g u r a t i n n , e i t h e r b y c o v a l e n t : . o r b y i o n i c boi7d f c~r-mati.t3n.

Whi crttever -For.mal. b o n d t y p e is he:l i evecl . t o e:.::i st t h e h i g h e l ~ i c x t r - o n e g a . t . i v i t y o f f l c-tori nci w i l l s ~ i s c t r - e t h a t % h e d e s i r e d

c ~ o n f i g u r a t i c t n is n e a r l y r e a c h e d . k'or t 1 1 j . s r e a s o n , irr t t 1 j . s n o t e , j t

~ . j i l l b e c o n v e n i e n ' t t o r e g a r d f l ~ i ! n r - i d e ( F - - , l s " 2 s = 2 p h : j a s t h e s t a r t i n g p o i r i t f o r t h e v a r i o ~ t s e l . e & o r ~ i c . t : r a n s i t i a n ? + t o b e d i s c ! - t s s e d b e 1 a w . The? c r e a t i o n o f a is c o r e vacanc:y ? ' t n g i v e % ~ ; ~ 2 s " 2 p ~ > i n a c h e m i c a l l y bot.rnd f l u o r i d e w i l l 1.eaci t o r e ? l a : . : a . t i a n b y e i t h e r X - r a y ( ' t o 1.55z2r52:Zp5) or- ta)i At..tger e l a c t r o n ? ' t o I s"ZsZ:!2f3" etc: i e m i ssi o n i tr whi t r t l the:

o r b i t a l s a f . t h e Cir1a.l. s t a t e w i l l . b e l . n v o l . v e d i n I:sondj.ng. I n % h e X - r a y s p e c : t r u m h i g h - e n e r g y s a t e l l i t e s a r e a l s c a ( ~ l h z e r v e d i K a,>.-) w h i c h a r e I3el i e v e t j E 1 3 t n u-esr.tl.t f r o r n .t:r-ansi t i r 3 n s o f t h e % y p e 1.s'2s-"2p5 -3

3, =-.ir-.-..-p'. ,,>--T *-a> Cllno i n X - r a y p h o t o e l e c . t r - o n s p e c r t r o s c c s p y s a t e l % I, t e s a r e a b s e r v e d , t3ci.t o n , t h e l o w k i n e t i c e n e r g y ? s i d e o f , t h e F 1 s p e a k , w h i c h a r e r a t i . o n a l i s e d E 2 3 a s 'stial.::e--cq> ' i l s * 2 s 2 2 ~ 3 ~ n p * ) o r 'shz3I::e-of f '

(ls42s":7:psi p e a i : : ~ . :It. i . s c l e a r ? r a m t h e c o n 4 i g t . t r a t i o r . I ~ ; i . n v o l v e d i n t h e s e p r - t ~ c e s n e s . t h a t t h e e n e r g i e s o f t h e v a i - i o u s p e a k s al-rc'i s a t e : l l i t e s a r e i n t e r c o n n e c t e d . Fi,trt.hr.rrnc:~re? p r e v i o u s X - r a y ernisjcji.orI IXF) a n d S.-r-ay p l 3 n t a e l e c t 1 - ( 3 1 1 (XPI s t i t d i e s C 3 1 h a v e s h o w n t h a t . h o ' t h e n e ~ - ' g i e s ancl j.n.tens;i.ti smj o f peal::% a n d s a t e l I. i t e s cart v a r y , s o r n e . t i m e s

d r - a i n a . t i c r a l l y , w i t h tl..~e c:heniicral env:i.r-onment c3f %I.?e C l i . t o r i . d e anir-?n.

T h i s n o t e nett1 i n e s t h e c : c l r r ~ + l . a t j . o n e the\+: e x j . s t b e t w e e n t h e v a r i o u s

~ q 7 e c t : r - a l fea.l:c.tr~?~i a n d e t s p e c i a l l y % h o s e b e t w e e n K a n d ' s h a l : : ~ - u p , --of 4 ' p e a k s .

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:19879136

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3. F l u o r i d e Energy L e v e l s

An e n e r g y l n v e l . d i aqrarrr t o c o r r e l a t e vat-i oc8.s; z e r o , % : i n g l y a n d c l o ~ t t ~ l y i o n i s e d s t a t e s o f i s o l a t e d f l u o r i d e w i t h t h o s e 0 . F hyclr-ogen C:Lr.loride a r e s h o w n i n f i r j l . l r e 1 . t.fycJroqen f l u n r . j . d e w a s c h o s e r ? L:,ec::inc.ise .ttie c : l o s ~ pro:.: iini:ty o f a h i g h l y p o l a r - i , s i n g pr-okon may we1 1 r e p r e s e n t a n e x t r e i n e c a s e o f !:he e 1 e c t . r o m s t a t . i ~ e f f ec:t whi.ch f I.!-tor-ide w i 1 I. enc:csunter i n c z r y s t a l I.za.tti.ce!s a n d a l s o b e c a u s e e ? . : . t e r ~ s i v e s p e c t r - o r s c o p i c d a t a is a v a i l z ~ b l e L43. T1'1e c : u r r e l a t i o n I. i r i e s f o r FH'* a r e h o r i z o n t a l b e c a u s e i'. i . s asraumed t h a t t h e a p p r o a c h o f a czhar-ged p r o t o r i t o a net-ttr-a1 a t o m wj.l.1 n o t a f f e c t . i t s e n e r g y . A c o m p a r i s o n o f t h e a t t a c h e m e n t e r t t h a l p y S o r f l u o r i n e ( 3 . 4 8 e V ) E53 w i k h tl-tat o f t h e .Fir.;+: i a r t i s a . t i . o n e n e r q y f o r H F ( 1 6 . 0 5 e V i C47 ~ i ~ ~ g g e ~ : t ~ 3 t h a t t h e e l e c t . r o s l : a ' i i c . t : e r m +or- H*F.- i s 1 2 . 6 5 e V ! c a l c u l a t e d , 1 5 . 7 e V C 4 : I ) . R s , t h e f l t - t o r - i n e 1::: a XE e n e r g y v a r i e s v e r y 1 i t t l e w i t h c h e i n i c a l e n v i r o n m e n t i t w i 1 1 a s s u m e d c : o n s t a n t a t 6 7 6 . 5 e'J. T h e i n n i . - , a t i o n e?ner-gy 0 9 f l u o r i n e tcs t h e :f.s"2z."2p4, "P s t a t e i s 1 7 . 4 2 e V s o t h a t t h e k:LaxLz3 t t 7 t h e s a m e s t a t e s h o u l d h e 659. 1 eV:: a s s u m i n g . t h e I D

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t r a n s i t i o n s a r e , i n d e e d , ' s h a k e - o f f ' a n d n o t ' s h a i c e - u p '

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T h e t w o s i d e s o f f i g u r e 1 c a n b e c o n n e c t e d t o i n d i c a t e t h e e n e r g i e s o f t h e v a r i o u s s t a t e s o f f l u o r i d e a s t h e e l e c t r o s t a t i c p o t e n t i a l o f t h e e n v i r o n r n e r i t i s a l t e r e d ( i . e, d i f f e r e n t c r y s t a l l a t t i c e s ) . 4. R e s u l t s and D i s c u s s i o n

' S h a k e - . . u p , - o f f ' s p e c t r a f o r I. i thit.rm, s o d i ~ t r r ~ a n d p o t a s s i . i . t m f l c r o r i d e a r e s h o w n i n f i g c t r e 2 , ( t h e c o m p l e t e r a n g e o f peak::s is n o t s h o w n , i t a p p e a r s t o e x t e n d m o r e t h a n 5 0 v o l t s f r o m t h e m a i n p h o t o p e a k ) . W h i l s t r$.tril.::ing c h e m i c a l v a r i a . t i o r - 1 s a r e a p p a r e n t o n l y t h e r e s u l t s f o r L.iF w i l l b e c o n s i d e r e d h e r e . T h e o b s e r v e d p r i n c i p a l G u g e r e n e r g y is 6 5 1 . 3 e v ~ h i c t ? h a s h e e r i used a s t h e b a s i s f o r - t h e v e r - . k i c . a l 'L-IF' l i n e i n f i g . 1. T h i s l i n e i n d i c a t e s +:hat. t h e ~ i r ? q l . ~ t ancl t r i p l e t ' s h a k e - o f f '

s t a t e s s t i o ~ t l d b e 3 0 e V a n d .26 &V a b o v e t h e F I s pho.topeal.::, i n e : . : c e l l e n t a g r e e m e n t . b4ith t h e d a t a o f C i g . 2 . H u t a f i t - s t i o n i s a t i o n e n e r g y o f o n l y 8 e V is a l s n i n t j i c a t e d , w h i c h is n w t i1-I st-rch g o o d a c c o r d w i t h t h e o b s e r v e d v a l u e o f 1 2 e V . 1.t. may 1 - d e l l b e t h a t . t h i s d i s c : r e p e n c y a r i s e s b e c a u s e o f t h e a p p r o > : irnalre n a t r - t r e o f t h e m o d e l , i n w h i c h a 1 1 c h e m i c a l ~ p l i t t i r ~ g o f 1 . e v e l s d u e t o c r y s t a l f i e l d artd b o n d f o r m a t i o n h a s b e e n i g n o r e d .

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f l uor i de. S t a t e s a s s c 3 c - i a t e d w i l r h .f 1 , t . t ~ ~ - i de n e g a t i v a a n i or-i ar-c+ st-~own

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~ z i n g l e p o s i t i v e c h a r g e - * - - - . X - r a y e m i s s i o n % r a n ! % i . t j . o r i s a r e s h n w n a s p a r a 1 ley. v e r t i c a l l i n e s , A ~ t g e r - emj.sz+j.on a% brnj::en v e r i r i c a l l i n e s . E n e r g i e s h a v e b e e n roctncled Ir.@ the f i . r s t d e c i m a l p l a c : ~ ? ~

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JOURNAL DE PHYSIQUE

5. C o n c l u s i o n s

B y m e a n s c?f a sing:l.E? e n e r g y l e v e l diagr.*rninc j.t :is p o s s i t2. i e to cor-r-$21 a t e X . - r a y erni s s i . o n , 1 z h o t o e l . e c t r o n a n d A u g e r a l e c t r - c m c n e r g i r+s f o r t h e f l u o r - i d e a n i o n .

F;.gut-e 2.

' S h a k e - . - u p , - - o f f ' s p e c t r a l r e g i o n f o r f 1 1 - t a r - i n e I s .

E n e r g y s c a l e i n d i c a t e s s e p a r - a t i a n ( t o 1 o 4 ~ r

k i n e t i c e n e r g y ) f r o m t h e f l ! . t o r i n e is p h o t o - p e a l . : :

A c k n o w l e d g e m e n t a

T h e a c t t t . t o r s wi 5t.t t o . t h a n k t h e SERC Sclr a R e s ~ - ? i ~ r ~ . h ASS^ s t a n t s h i p b-~hj. c t i e n a b l . e d R 1.1 t o c a r f F - y c x t t t h e w o r k r e p o r t e d h e r - e . "St?ey a r e a l s o

y r a t e f u l ,to t . h e R o y a l S o c i e t y

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t h e C e n t r a l . R e s e a r c h Ft.tnd o f 1-onclan U n i v e r s i t y a n d . t h e SERC f o r f u n d s fczt- t h e p u t - c h a s e r ~ f e q u i p i n e n t . F i n a l l y t h e y w i s h t a s:.:presr; t h e i r t h a n k s t o D r . P. W e i g h t m a n f c ) r h e 1 p f u l ancl %-ti mi-tl a t i n g d i s c u s s i o n s .

R e f e r e n c e s

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K. arid P.IAKAI~L~WA, t.{. X - r a y s p e c t r a arrd e . l e c t r r . i n i c s . t r i i i : t n r e <.>I' m a t t e r , P L I ~ J . 1 : n s . t . o f Ivle(ra% P h y s i c s , fic:ad.

o f S c i .

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U k r - a i n e ?:iSR, [::iev !.JS9R, 2 i Y . 9 t . Y ; 122

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E 4 J StiAW, ti. !A. a n d ~T'tiOMAG, T. D. Phy:;.; R e v . . l l A (1975) 1 4 . 9 % C51 tJCITUF., H. and I.:[NEBERGEI"(, W. C . J , P h y ~ . C h e ~ , R e f , U a t a 4 ( 1 9 7 5 ) I"" ,~.:;9

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