Notizen 1337

Notizen 1337

Die Struktur des K

³

PS

⁴

H

²

0

C r y s t a l S t r u c t u r e o f K3P S4 • H20 K l a u s V o l k u n d H e r b e r t S c h ä f e r * A b t e i l u n g I I f ü r A n o r g a n i s c h e C h e m i e i m E d u a r d - Z i n t l - I n s t i t u t

d e r T e c h n i s c h e n H o c h s c h u l e i n D a r m s t a d t , H o c h s c h u l s t r a ß e 4 , D - 6 1 0 0 D a r m s t a d t Z . N a t u r f o r s c h . 3 4 b , 1 3 3 7 - 1 3 3 8 ( 1 9 7 9 ) ; e i n g e g a n g e n a m 2 1 . J u n i 1 9 7 9

T e t r a t h i o p h o s p h a t e , C r y s t a l S t r u c t u r e

K 3 P S 4 • H20 c r y s t a l l i z e s i n t h e o r t h o r h o m b i c s y s t e m , s p a c e g r o u p P 2 i 2 i 2 w i t h a = 1 2 0 5 ± 1 p m , b = 1 2 5 1 ± 1 p m , c = 6 6 7 . 8 ± 5 p m . T h e r e a r e i s o l a t e d P S 43 -- t e t r a h e d r a i n t h e s t r u c t u r e w i t h P - S - b o n d l e n g t h s b e t w e e n 2 0 2 . 9 a n d 2 0 6 . 1 p m .

D i e S t r u k t u r d e s w a s s e r f r e i e n K a l i u m t e t r a t h i o - p h o s p h a t s i s t s e i t l ä n g e r e r Z e i t b e k a n n t [ 1 ] . N a c h [ 2 ] e x i s t i e r t n o c h e i n M o n o h y d r a t d i e s e r V e r - b i n d u n g

(K3PS4 • H2O),

d a s i n F o r m f a r b l o s e r , a n f e u c h t e r L u f t z e r f l i e ß l i c h e r , v i e r s e i t i g e r , g e d r u n g e - n e r P r i s m e n k r i s t a l l i s i e r t . E s g e l a n g u n s , d i e S t r u k - t u r d i e s e r V e r b i n d u n g a u f z u k l ä r e n .

E i n n a c h [ 2 ] d a r g e s t e l l t e r s t ä b c h e n f ö r m i g e r K r i - s t a l l w u r d e i n e i n M a r k r ö h r c h e n e i n g e s c h m o l z e n u n d m i t P r e c e s s i o n - u n d W e i ß e n b e r g - M e t h o d e n u n t e r s u c h t . D a n a c h k r i s t a l l i s i e r t d i e V e r b i n d u n g o r t h o r h o m b i s c h m i t d e n Z e l l k o n s t a n t e n d e r T a b . I . D i e I n t e r f e r e n z b e d i n g u n g e n , R e f l e x e A 0 0 n u r v o r - h a n d e n f ü r h = 2n u n d O f c O n u r v o r h a n d e n f ü r k = 2n, f ü h r t e n z u r R a u m g r u p p e P 2 i 2 i 2 . Z u r S t r u k - t u r b e s t i m m u n g w u r d e n d i e I n t e n s i t ä t e n v o n 1 8 8 4 R e f l e x e n a n e i n e m a u t o m a t i s c h e n Z w e i k r e i s d i f -

f r a k t o m e t e r ( F a . S t o e & G e , M o K a , G r a p h i t m o n o - c h r o m a t o r , & < 3 0 ° ) g e m e s s e n . N a c h d e n ü b l i c h e n K o r r e k t u r e n v e r b l i e b e n 1 6 8 7 s y m m e t r i e u n a b h ä n - g i g e R e f l e x e . D i e B e s t i m m u n g a l l e r A t o m l a g e n g e - l a n g d u r c h d i r e k t e P h a s e n b e s t i m m u n g s m e t h o d e n m i t H i l f e v o n M U L T A N [ 3 ] . D i e s o e r h a l t e n e n P a r a - m e t e r w u r d e n n a c h d e r M e t h o d e d e r k l e i n s t e n F e h l e r q u a d r a t e o p t i m i e r t [ 4 ] . N a c h E i n f ü h r u n g

A b b . 1 . P r o j e k t i o n d e r A t o m a n o r d n u n g d e s

K 3 P S 4 • H20 a u f d i e a , 6 - E b e n e ( g r o ß e K r e i s e ^ K + - I o n e n , g e p u n k t e t e K r e i s e == H²0 - M o l e k ü l e , d i e P S 4 - T e t r a e d e r s i n d d u r c h B i n d u n g s s t r i c h e h e r v o r g e h o b e n ) .

T a b . I . D i e k r i s t a l l o g r a p h i s c h e n D a t e n d e s K 3 P S 4 • H20 . ( I n K l a m m e r n d i e S t a n d a r d a b w e i c h u n g e n . ) D e r i s o t r o p e T e m p e r a t u r f a k t o r i s t a l s e x p [ — 8 TZ2 • U • s i n2 # / A²] , d e r a n i s o t r o p e T e m p e r a t u r f a k t o r a l s

e x p [ — 2n2 (h2a*2Un + k2b*2U22

+ l

²

c*

²

U33 + 2hka*b*\J

¹²

+ 2hla*c*V

¹³

+ 2klb*c*~U

²³

]

d e f i n i e r t . R a u m g r u p p e P 2\2\2 V o l u m e n d e r

A c h s e n [ p m ] a = 1 2 0 5 ± 1 E l e m e n t a r z e l l e [ p m3] 1 0 0 6 , 4 • 1 0⁶ 6 = 1 2 5 1 ± 1 Z a h l d e r F o r m e l e i n h e i t e n 4

c = 6 6 7 , 8 ± 5 D i c h t e r ö n t g , [ g / c m3] 1 , 9 5

A t o m l a g e n X

y

^z

Un u

22

U33 u

23

U13 Ul

2

4 K ( l ) a u f 4 c 0 , 8 8 6 9 ( 4 ) 0 , 1 2 9 2 ( 3 ) 0 . 8 6 3 1 ( 7 ) 5 3 6 ( 2 6 ) 3 9 9 ( 1 8 ) 5 2 6 ( 2 2 ) - 7 ( 1 8 ) 8 3 ( 2 1 ) 1 2 9 ( 1 8 ) 4 K ( 2 ) „ „ 0 , 2 9 9 6 ( 4 ) 0 , 0 2 7 9 ( 3 ) 0 , 2 9 2 3 ( 6 ) 3 8 3 ( 2 2 ) 3 4 2 ( 1 7 ) 2 8 9 ( 1 6 ) 7 0 ( 1 5 ) 3 8 ( 1 7 ) 6 3 ( 1 7 ) 4 K ( 3 ) „ „ 0 , 5 5 2 5 ( 3 ) 0 , 1 8 6 5 ( 3 ) 0 , 6 0 2 3 ( 5 ) 3 0 8 ( 1 8 ) 3 3 7 ( 1 5 ) 3 5 0 ( 1 6 ) - 3 ( 1 4 ) 1 9 ( 1 5 ) - 5 0 ( 1 3 ) 4 P „ „ 0 , 2 3 8 4 ( 3 ) 0 , 1 6 0 1 ( 2 ) 0 , 7 6 0 6 2 0 9 ( 1 8 ) 1 7 5 ( 1 2 ) 2 1 9 ( 1 4 ) - 5 ( 1 1 ) 1 1 ( 1 3 ) 1 3 ( 1 2 ) 4 S ( l ) „ „ 0 , 3 5 7 8 ( 3 ) 0 , 0 4 4 2 ( 3 ) 0 , 8 0 2 0 ( 6 ) 2 9 0 ( 1 9 ) 2 0 8 ( 1 3 ) 3 2 9 ( 1 7 ) - 9 ( 1 3 ) - 8 ( 1 5 ) 7 1 ( 1 3 ) 4 S ( 2 ) „ „ 0 , 1 1 1 1 ( 3 ) 0 , 0 9 4 2 ( 3 ) 0 , 6 0 4 4 ( 6 ) 2 7 8 ( 2 0 ) 2 9 3 ( 1 5 ) 3 5 7 ( 1 7 ) - 3 3 ( 1 5 ) - 5 4 ( 1 6 ) - 3 3 ( 1 5 ) 4 S ( 3 ) „ „ 0 , 3 0 5 0 ( 4 ) 0 , 2 8 8 3 ( 3 ) 0 , 6 1 5 4 ( 7 ) 3 0 5 ( 2 0 ) 2 4 8 ( 1 5 ) 4 7 7 ( 2 1 ) 1 0 2 ( 1 6 ) 2 8 ( 1 9 ) - 1 4 ( 1 4 ) 4 S ( 4 ) „ „ 0 , 1 8 2 7 ( 4 ) 0 , 2 0 9 1 ( 3 ) 0 , 0 3 4 0 ( 6 ) 4 0 0 ( 2 4 ) 3 9 2 ( 1 9 ) 2 7 3 ( 1 6 ) - 6 9 ( 1 5 ) 5 3 ( 1 7 ) 9 4 ( 1 8 ) 4

0 „ „

0 , 5 1 5 1 ( 1 2 ) 0 , 1 2 8 0 ( 1 1 ) 0 , 1 8 6 7 ( 1 9 ) 4 8 1 ( 3 2 )

i ? - W e r t : 0 , 0 7 8 ( 1 6 8 7 s y m m e t r i e u n a b h ä n g i g e R e f l e x e ) .

* Sonderdruckanforderungen an Prof. Dr. Herbert Schäfer. 0340-5087/79/0900-1337/$ 01.00/0

1338 Notizen

T a b . I I . A t o m a b s t ä n d e [ p m ] u n d B i n d u n g s w i n k e l [ ° ] i m K 3 P S 4 • H 2 O . ( I n K l a m m e r n d i e S t a n d a r d a b w e i c h u n g e n ) .

a ) P S 4 - T e t r a e d e r

P - S ( 2 ) 2 0 2 , 9 ( 5 ) S ( 2 ) - P - S ( 4 ) 1 0 9 , 5 ( 2 )

- S ( 4 ) 2 0 3 , 9 ( 5 ) S ( 2 ) - P - S ( 3 ) 1 1 1 , 9 ( 2 )

- S ( 3 ) 2 0 4 , 0 ( 5 ) S ( 2 ) - P - S ( l ) 1 0 8 , 1 ( 2 )

- S ( l ) 2 0 6 , 1 ( 5 ) S ( 4 ) - P - S ( 3 ) 1 0 8 , 6 ( 2 )

S ( 4 ) - P - S ( l ) 1 0 8 , 7 ( 2 ) S ( 3 ) - P - S ( l ) 1 1 0 , 0 ( 2 ) b ) K o o r d i n a t i o n s p o l y e d e r d e r K - I o n e n

K ( l ) - S ( 2 ) 3 2 3 , 7 ( 6 ) K ( 2 ) - S ( 4 ) 3 1 7 , 7 ( 6 ) K ( 3 ) - S ( 2 ) 3 1 5 , 1 ( 6 )

- S ( 4 ) 3 2 5 , 8 ( 6 ) - S ( 2 ) 3 1 9 , 3 ( 6 ) - S ( 4 ) 3 1 7 , 3 ( 6 )

- S ( 2 ) 3 2 8 , 5 ( 6 ) - S ( 3 ) 3 3 0 , 8 ( 6 ) - S ( l ) 3 2 3 , 3 ( 6 )

- S ( 3 ) 3 5 0 , 0 ( 6 ) - S ( l ) 3 3 5 , 4 ( 6 ) - 8 ( 3 ) 3 2 4 , 4 ( 6 )

- 8 ( 1 ) 3 6 8 , 2 ( 6 ) - S ( l ) 3 4 8 , 1 ( 6 ) - S ( l ) 3 3 5 , 7 ( 6 )

- S ( 3 ) 3 7 6 , 4 ( 6 ) - 8 ( 3 ) 3 9 0 , 8 ( 6 ) - S ( 3 ) 3 3 8 , 7 ( 6 )

- 8 ( 4 ) 3 8 7 , 4 ( 6 ) - O 2 9 7 ( 1 ) - O 2 9 1 ( 1 )

- O 3 4 2 ( 1 ) - O 3 0 5 ( 1 )

a n i s o t r o p e r T e m p e r a t u r f a k t o r e n f ü r d i e P h o s p h o r - , K a l i u m - u n d S c h w e f e l a t o m e e r g a b s i c h e i n J ? - W e r t v o n 0,078. A u f e i n e B e s t i m m u n g d e r L a g e d e r W a s s e r s t o f f a t o m e w u r d e v e r z i c h t e t . I n T a b . I s i n d d i e k r i s t a l l o g r a p h i s c h e n D a t e n d e s K3PS4 • H 2 O z u - s a m m e n g e s t e l l t . E i n e L i s t e d e r b e o b a c h t e t e n u n d b e r e c h n e t e n S t r u k t u r f a k t o r e n w i r d v o n d e n A u t o r e n a u f A n f r a g e z u r V e r f ü g u n g g e s t e l l t .

A b b . 1 z e i g t e i n e P r o j e k t i o n d e r S t r u k t u r a u f d i e ( O O l ) - E b e n e . I n T a b . I I s i n d d i e w i c h t i g s t e n B i n - d u n g s l ä n g e n u n d - w i n k e l a u f g e f ü h r t . E r w a r t u n g s - g e m ä ß s i n d d i e P h o s p h o r a t o m e v o n v i e r S c h w e f e l - a t o m e n v e r z e r r t t e t r a e d r i s c h u m g e b e n . D i e P - S - A b s t ä n d e l i e g e n z w i s c h e n 202,9 u n d 2 0 6 , 1 p m u n d s t i m m e n d a m i t m i t d e n e n i m w a s s e r f r e i e n K3PS4

s e h r g u t ü b e r e i n [1]. D i e K a l i u m i o n e n s i n d s e h r u n - r e g e l m ä ß i g k o o r d i n i e r t . U m d i e K ( l ) - I o n e n f i n d e n s i c h 7 S u l f i d i o n e n u n d 1 W a s s e r m o l e k ü l , u m d i e K ( 2 ) - I o n e n h i n g e g e n 6 S u l f i d i o n e n u n d 2 W a s s e r - m o l e k ü l e . F ü r d i e s e I o n e n e r g i b t s i c h s o m i t d i e K o o r d i n a t i o n s z a h l 8. D i e K ( 3 ) - I o n e n s i n d d e m - g e g e n ü b e r v o n 6 S u l f i d i o n e n u n d 1 W a s s e r m o l e k ü l u m g e b e n , so d a ß d i e K o o r d i n a t i o n s z a h l 7 r e s u l t i e r t . D a b e i s i n d d i e K ( 3 ) - S - b z w . K ( 3 ) - 0 - A b s t ä n d e i m M i t t e l k ü r z e r a l s d i e e n t s p r e c h e n d e n A b s t ä n d e i n d e n b e i d e n a n d e r e n K - P o l y e d e r n .

D e r D e u t s c h e n F o r s c h u n g s g e m e i n s c h a f t s o w i e d e m F o n d s d e r C h e m i s c h e n I n d u s t r i e d a n k e n w i r f ü r d i e F ö r d e r u n g d i e s e r U n t e r s u c h u n g e n .

[ 1 ] H . S c h ä f e r , G . S c h ä f e r u . A . W e i ß , Z . N a t u r - f o r s c h . 2 0 b , 8 1 1 ( 1 9 6 5 ) .

[ 2 ] F . E p h r a i m u . R . S t e i n , C h e m . B e r . 4 4 , 3 4 0 7 ( 1 9 1 1 ) .

[ 3 ] G . G e r m a i n , P . M a i n u . M . M . W o o l f s o n , A c t a C r y s t a l l o g r . A 2 7 , 3 6 8 ( 1 9 7 1 ) .

[ 4 ] G . S h e l d r i c k , S H E L - X - P r o g r a m m s y s t e m , C a m - b r i d g e , u n v e r ö f f e n t l i c h t .