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

摘要

The dimers [Cu_2(dppm)_2(CN-t-Bu)_3](BF_4)_2 and [Ag_2(dppm)_2(CN-t-Bu)_2](X)_2 (X~ = BF_4~~,CI0_4~~) and the coordination polymers {[M(diphos)(CN-t-Bu)_2]BF_4}_n (M - Cu,Ag; diphos = bis(diphenylphosphino)butane (dppb),bis-(diphenylphosphino)pentane (dpppen),bis(diphenylphosphino)hexane (dpph)),{[Ag_2(dppb)_3(CN-t-Bu)_2](BF_4)_2}_n,and {[Ag(dpppen)(CN-f-Bu)]BF_4}_n have been synthesized and fully characterized as model materials for the mixed bridging ligand polymers which exhibit the general formula {[M(diphos)(dmb)]BF_4}_n (M = Cu,Ag; dmb = 1,8-diisocyano-p-menthane) and {[Ag(dppm)(dmb)]CI0_4}_n.The identity of four polymers ({[Ag(dppb)(CN-t-Bu)_x]BF_4}_n (x= 1,2),{[Ag_2(dppb)_3(CN-t-Bu)_2](BF_4)_2}_n,{[Ag(dppm)(dmb)]CI0_4}_n) and the two dimers has been confirmed by X-ray crystallography.The structure of {[Ag(dppm)(dmb)]CI0_4}_n exhibits an unprecedented 1-D chain of the type "{Ag(dmb)_2Ag(dppm)_2~2+}_n",where d(Ag-Ag) values between tetrahedral Ag atoms are 4.028(1) and 9.609(1) A for the dppm and dmb bridged units,respectively.The {[Ag(dppb)(CN-t-Bu)_x]BF_4}_n polymers (x = 1,2) form zigzag chains in which the Ag atoms are tri- and tetracoordinated,respectively.The {[Ag_2(dppb)_3(CN-t-Bu)_2](BF_4)_2}_n polymer,which is produced from the rearrangement of {[Ag(dppb)(CN-t-Bu)_2]BF_4}_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 mus.These emissions are assigned to a metal-to-ligand charge transfer (MLCT) of the type M(l) - pi*(NC)/pi*(PPh_2).