Silver(I) Double and Multiple Salts Containing 1,5-Hexadiyne-1,6-diide and Nitrate Ions

Five new silver­(I) double and triple salts containing
conformationally flexible 1,5-hexadiyne-1,6-diide (−CCCH2CH2CC–, C6H42–) and nitrate ions,
namely Ag2C6H4·7AgNO3 (1), Ag2C6H4·3AgNO3·2AgF
(2), Ag2C6H4·4AgNO3·2L1 (3; L1 = imidazole),
Ag2C6H4·2AgNO3·2AgL2 (4; HL2 = pyrazole),
and Ag2C6H4·4AgNO3·2L3 (5; L3 = 3,5-dimethylpyrazole),
have been synthesized, in which the C6H42– species was found to adopt two distinct configurations:
anti in 1 and 3 and gauche in 2, 4, and 5. Complex 1 features
an unusual Ag5⊂C6H4⊃Ag4 aggregate as the basic building unit, and such aggregates
are interconnected by the nitrate ions to generate a three-dimensional
coordination network. Complex 2 exhibits a three-dimensional
coordination network constructed with compact C6H4⊃Ag7 units, nitrate ions, and fluoride ions that
assume a μ3 trigonal-pyramidal coordination mode.
In 3, the Ag4⊂C6H4⊃Ag4 aggregates are stabilized by nitrate groups
and imidazole ligands to generate a layer structure. In complex 4, infinite chains each bearing deprotonated pyrazole ligands
attached to the silver backbone are weaved by nitrate groups to form
a three-dimensional coordination architecture. In 5 the
3,5-dimethylpyrazole ligands coordinate to silver atoms at the upper
surface of each coordination layer, and the layers are interconnected
to form a three-dimensional supramolecular network via hydrogen bonding.