Synthesis and spectroscopic characterization of platinum azetidinone blue

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Abstracts

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SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF P L A T I N U M AZETIDINONE BLUE I. B l a c k , t K. R o t h e n b e r g e r , % P. S t e i n "T~ J'Department of C h e m i s t r y , Duquesne University, Pittsburgh, PA 15282 ±Department of E n e r g y , Pittsburgh Energy Technology Center, Pittsburgh, PA 15236 The synthesis and spectral properties, including UV-vis, EPR and resonance Raman (rE) , a r c r e p o r t e d for platinum azetidinone blue (i) . T h e d a t a a r e compared with cis-diamminep!atinum e-pyrrolidone blue (_2)I a n d c --i s - d i a m m i n e p l a t i n u m <~-pyridone blue (3) ~. The cation of (3), P t 4 ( N H p 8 (Cs}{,NO).~+ , ~ is known to be a tetranuclear platinum chain, consisting of t w o amidate bridged dimers with the exocyclic oxygens coordinated to t h e i n n e r Pt a t o m s , P t ° a n d P t , , as shown below. Formation of (I) is observed by a c i d i f y i n g a solution of P t ( N H . ) ~ (}I2@)~ ~+-.. and azetidinene (!2 -pr(~p i o P t - Pt .... Pt - - - Pt lactam) , previously incubated at 60o( , a n d O ° C NH3 NH3 for several d a y s , to ] .SM HNO A d d i t i o n a l conc. q+ H N O ~ t u r n s ~ h e b l u e soiuFIGURE I. Pt~+~ cation t i o n r e d a n d NaNO 3 turns schematically showing the the so!utio~ green. four bridging ligands.

..;I <1

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The optical bands of (I) at 6 8 4 n m ;ind 5 1 7 n m the EPR, measured in f r o z e n solutions (g,;=i . 9 7 1 g~=2.4i4) , are comporable with t h o s e of (2) a n d T h e rR s p e c t r a of the Pt~+ c a t i o n s me ~ s u r e .0(Pt

ring

size,

1. 2. 3.

is

expected

to

shorten

the

ligar;d

and and (3).

bite

K. H a t s u m o t o , ['. Watanabe, J. Am:__ch£K. !0_£., 108, 1308 (1986) . N. K. B a r t o n , C. C a r a v a n a , .qo L [ p p a r d . ibid. , I01, 1269 (197q) . H. K. Mahtap,~ ~ }'. S t e i n , ~bid.. ill. !505 (]989) .