Preparation and Solid-State Characterization of Mixed-Ligand Coordination/Organometallic Oligomers and Polymers of Copper(I) and Silver(I) Using Diphosphine and Mono- and Diisocyanide Ligands

The dimers [Cu2(dppm)2(CN-t-Bu)3](BF4)2 and [Ag2(dppm)2(CN-t-Bu)2](X)2 (X- = BF4-, ClO4-) and the coordination
polymers {[M(diphos)(CN-t-Bu)2]BF4}n (M = Cu, Ag; diphos = bis(diphenylphosphino)butane (dppb), bis(diphenylphosphino)pentane (dpppen), bis(diphenylphosphino)hexane (dpph)), {[Ag2(dppb)3(CN-t-Bu)2](BF4)2}n, and
{[Ag(dpppen)(CN-t-Bu)]BF4}n have been synthesized and fully characterized as model materials for the mixed
bridging ligand polymers which exhibit the general formula {[M(diphos)(dmb)]BF4}n (M = Cu, Ag; dmb = 1,8-diisocyano-p-menthane) and {[Ag(dppm)(dmb)]ClO4}n. The identity of four polymers ({[Ag(dppb)(CN-t-Bu)x]BF4}n
(x = 1, 2), {[Ag2(dppb)3(CN-t-Bu)2](BF4)2}n, {[Ag(dppm)(dmb)]ClO4}n) and the two dimers has been confirmed by
X-ray crystallography. The structure of {[Ag(dppm)(dmb)]ClO4}n exhibits an unprecedented 1-D chain of the type
“{Ag(dmb)2Ag(dppm)22+}n”, where d(Ag...Ag) values between tetrahedral Ag atoms are 4.028(1) and 9.609(1) Å for
the dppm and dmb bridged units, respectively. The {[Ag(dppb)(CN-t-Bu)x]BF4}n polymers (x = 1, 2) form zigzag
chains in which the Ag atoms are tri- and tetracoordinated, respectively. The {[Ag2(dppb)3(CN-t-Bu)2](BF4)2}n polymer,
which is produced from the rearrangement of {[Ag(dppb)(CN-t-Bu)2]BF4}n, forms a 2-D structure described as a
“honeycomb” pattern, where large {Ag(dppb)+}6 macrocycles each hosting two counterions and two acetonitrile
guest molecules are observed. Properties such as glass transition temperature, morphology, thermal decomposition,
and luminescence in the solid state at 293 K are reported. The luminescence bands exhibit maxima between 475
and 500 nm with emission lifetimes ranging between 6 and 55 μs. These emissions are assigned to a metal-to-ligand charge transfer (MLCT) of the type M(I) → π*(NC)/π*(PPh2).