Table 3.

Ln⋯Ln, Ln-N and Ln-O Distances (Å), Bond Valences (ν_Ln,j)^a and Bond Valence Sums (V_Ln)^b in the Crystal Structures of [Yb₂(L3)(hfac)₆] (1), [Yb₂(L4)(hfac)₆] (3) and [Eu₂(L5)(hfac)₆] (4).

	[Yb2(L3)(hfac)6]	[Yb2(L4)(hfac)6]	Eu2(L5)(hfac)6]
Ln-Nbzim c /Å	2.443(4)	2.476(4)	2.581(1)
Ln-Npy /Å	2.519	2.526	2.61
Ln-O d /Å	2.38(8)	2.36(7)	2.43(2)
Ln⋯Ln /Å	12.624	14.77	14.928
νLn, N(bzim)c	0.359(4)	0.328(4)	0.322(1)
νLn,N(py)	0.292	0.287	0.297
νLn,Od	0.33(6)	0.34(6)	0.35(2)
VLn	2.964	2.980	3.039

^aν_Ln,j = e^{[(R_Lnj−d_Ln,j)/b]}, whereby d_Ln,j is the Ln-donor atom j distance. The valence bond parameters R_Ln,N and R_Ln,O are taken from refs 41e,f and b = 0.37 Å.

^b$V_{\text{Ln}}={\displaystyle \sum _j}{\nu }_{\text{Ln},j}$.⁴¹

^c,dEach value is the average of two^c or six^d bond distances and the numbers between brackets correspond to the standard deviations affecting the average values (the original uncertainties affecting each bond length are given in Tables S4, S8 and S10; bzim = benzimidazole and py = pyridine).