Controlling the Dimensionality of Metal−Metal Bonded Rh24+ Polymers by the Length of the Linker. A Disciplined Example of Crystal Engineering

Abstract
Reaction of the molecular loop [Rh2(cis-DAniF)2(CH3CN)]2(malonato)2, DAniF = N,N‘-di-p-anisylformamidinate, with 2 equiv of 2,2‘,3,3‘,5,5‘,6,6‘-octafluoro-4,4‘-biphenyldinitrile gives a linear tubular structure with Rh−Rh distances of 2.435(1) Å. A comparison of the structures obtained with this molecular loop but employing other linkers support the idea that longer linkers favor one-dimensional structures while shorter linkers favor two-dimensional structures because of the increased clashing between the large p-anisyl groups. Crystallographic data at 213(2) K for {[Rh2(cis-DAniF)2]2(O2CCH2CO2)2(NCC6F4C6F4CN)2}·6.8nCH2Cl2 are: monoclinic, P21/m, a = 11.802(1), b = 28.303(2), c = 18.820(2) Å, β = 95.673(2)°, and Z = 2.