“…Consequently, the entropy change on ordering will be much reduced compared to a more isotropic system and may prevent specific heat measurements from detecting a transition [7]. For this reason sensitive magnetic measurement techniques such as muon-spin relaxation (µ + SR) have found a use in detecting the transitions to long range magnetic order that allow us to quantify the strength of the interchain exchange and reveal how well real materials are described by idealised models [9,6,10] In this paper we present µ + SR measurements on two different 1D coordination polymer systems: (i) the quasi-1D Heisenberg antiferromagnet CuF 2 (pyz), built from (boaDTDA) is the radical ligand 4-(benzoxazol-20-yl)-1,2,3,5-dithiadiazolyl and hfac = 1,1,1,5,5,5-hexafluoroacetylacetonato [12,13]. In both systems, the muon relaxation is dominated by the magnetism of the nuclear spins in the high-temperature paramagnetic regime owing to the rapid fluctuations of the electronic spins on the timescale of muon spin precession.…”