Studies on rare‐earth carboxylates. IV. Crystal chemical data on Ln(CH 3 Ch 2 CH 2 COO) 3 .2H 2 O, where Ln=Nd, Tb, Ho, Er, Tm, Yb or Y

The rare‐earth n ‐butyrate dihydrates Ln(C 4 H 7 O 2 ) 3 .2H 2 O (where Ln = Nd, Tb, Ho, Er, Tm, Yb or Y) were synthesized and the structural parameters determined employing X‐ray powder diffraction techniques. The salts are isomorphous and possess monoclinic symmetry with space group P 2 1 / m and contain four molecules per unit cell. Nd(CH 3 CH 2 CH 2 COO) 3 .2H 2 O: a = 12.69 (6), b = 14.34 (6), c = 10.31 (4) Å, β = 97.06  (36)°, V = 1862 Å 3 , D m = 1.655, D x = 1.575 Mg m −3 ; Tb(CH 3 CH 2 CH 2 COO) 3 .2H 2 O: a = 12.74 (2), b = 14.22 (4), c = 10.34 (3) Å, β = 98.02 (16)°, V = 1856 Å 3 , D m = 1.666, D x = 1.633 Mg m −3 ; Y(CH 3 CH 2 CH 2 COO) 3 .2H 2 O: a = 12.68 (2), b = 14.08 (4), c = 10.28 (2) Å, β = 98.57 (16)°, V = 1814 Å 3 , D m = 1.423, D x = 1.414 Mg m −3 ; Ho(CH 3 CH 2 CH 2 COO) 3 .2H 2 O: a = 12.62 (2), b = 14.00 (3), c = 10.22 (2) Å, β = 98.09 (13)°, V = 1789 Å 3 , D m = 1.727, D x = 1.716 Mg m −3 ; Er(CH 3 CH 2 CH 2 COO) 3 .2H 2 O: a = 12.60 (2), b = 14.02 (2), c = 10.19 (1) Å, β = 98.71 (13)°, V = 1780 Å 3 , D m = 1.707, D x = 1.733 Mg m −3 ; Tm(CH 3 CH 2 CH 2 COO) 3 .2H 2 O: a = 12.61 (2), b = 13.96 (2), c = 10.21 (2) Å, β = 98.30 (16)°, V = 1779 Å 3 , D m = 1.714, D x = 1.741 Mg m −3 ; Yb(CH 3 CH 2 CH 2 COO) 3 .2H 2 O: a = 12.64 (1), b = 13.92 (1), c = 10.19 (1) Å, β = 98.32 (10)°, V = 1773 Å 3 , D m = 1.745, D x = 1.762 Mg m −3 . The JCPDS Diffraction File No. for Er(CH 3 CH 2 CH 2 COO) 3 .2H 2 O is 34‐1991.