Inorganic Chemistry - American Chemical Society

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Downloaded by UNIV OF CALIFORNIA SAN DIEGO on August 17, 2015 | http://pubs.acs.org Publication Date: March 3, 1983 | doi: 10.1021/bk-1983-0211.ch010

Nonclassical Coordination Compounds JOHN P. FACKLER, JR. and JOHN D. BASIL Case Western Reserve University, Case Institute of Technology, Department of Chemistry, Cleveland, OH 44106

The topic "Non-Classical Coordination Compounds" is troub­ ling since it implies some knowledge of the meaning of both "classical" and "non-classical". To a young inorganic chemist reviewing some β-diketone work of ours, performed in the '60's, the term "classical" apparently meant work done a number of years ago. Obviously work being done today by modern young chemists is, therefore, "non-classical". Rather than accept the above definition, the fourth edition of "Advanced Inorganic Chemistry" by F. A. Cotton and G. Wilkinson (1) was consulted to see what it contains relevant to the "non­ -classical" behavior of metal-metal bonded compounds. Page 980 of this text presents an interesting illustration. H. Schmidbaur, in some beautiful work involving coordination of methyl ylides to metals, demonstrated that the dinuclear gold(I) ylide complex (Figure 1), reacts with dichlorine to form a dichloride which formally contains Au(II). As described below, there is a single bond between the two Au atoms. However, a remarkable non-classi­ cal species appears to be formed upon reaction with NaBPh. This cation is formulated as a Au(II) compound containing only two ligands coordinated to each metal atom. As any good inorganic chemist knows, a d metal ion such as Au(II) must be non-classi­ cal when it is only two coordinate. Even if a Au-Au bond is added, the species remains non-classical. Consequently, a careful examination of the system has been undertaken. After considerable study of the system and published results from Schmidbaur's lab­ oratory (2), it has been concluded that this ion is so non-classical that it is NON-EXISTENT. 4

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What Does E x i s t ? As i n d i c a t e d i n F i g u r e 2 , Schmidbaur and h i s students have reported (3) some very i n t e r e s t i n g r e a c t i o n s of the d i n u c l e a r Au(I) y l i d e complexes. Not only do these species o x i d a t i v e l y add halogen atoms to form Au(II) species ( F i g . 2 ; 3 ) a second mole of

0097-6156/83/0211-0201 $ 0 6 . 0 0 / 0 © 1983 American Chemical Society In Inorganic Chemistry: Toward the 21st Century; Chisholm, M.; ACS Symposium Series; American Chemical Society: Washington, DC, 1983.

INORGANIC C H E M I S T R Y : TOWARD T H E 2 1 S T C E N T U R Y

202

^CH - A u - C H / PMe 2 v

Me P 2

v

2

CH—Au-CH

2

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on August 17, 2015 | http://pubs.acs.org Publication Date: March 3, 1983 | doi: 10.1021/bk-1983-0211.ch010

12+ Me P / 2

CI CH — Au - CH

2

CH - A u - C H

2s

PMe„

%

CH —Au-CH CI 2

NaBPh,, CH —Au -CH

2

2

2

Figure 1. The remarkable "nonclassical" dinuclear gold(II) ion.

K^

KS Η

< Η ^ Η -Au-" ^ A u . 2

2

2

X

>fV

I

I Χ

χ/

Χ

R' 5

R. R'.CgH^CHj

(X« CLBr.I)

RrC H vR=CH 6

5

3

H? 2

I Η

Ψ2

Au 2

0

Au χ

ρ

R'

/

π

R 2

F/gwre 2.

H

H