Fmoc-D-Ala(cBu)-OH

The comproportionation reaction between Mn(II) and Mn(VII) reagents under acidic conditions has been investigated in the presence of pivalic acid as a route to new high oxidation state manganese pivalate clusters containing some Mn(IV). The reaction of Mn(O(2)CBu(t))(2) and NBu(n)(4)MnO(4) with an excess of pivalic acid in the presence of Mn(ClO(4))(2) and NBu(n)(4)Cl in hot MeCN led to the isolation of [Mn(8)O(6)(OH)(O(2)CBu(t))(9)Cl(3)(Bu(t)CO(2)H)(0.5)(MeCN)(0.5)] (1). In contrast, the reaction of Mn(NO(3))(2) and NBu(n)(4)MnO(4) in hot MeCN with an excess of pivalic acid gave a different octanuclear complex, [Mn(8)O(9)(O(2)CBu(t))(12)] (2). The latter reaction but with Mn(O(2)CBu(t))(2) in place of Mn(NO(3))(2), and in a MeCN/THF solvent medium, gave [Mn(9)O(7)(O(2)CBu(t))(13)(THF)(2)] (3). Complexes 1-3 possess rare or unprecedented Mn(x) topologies: 1 possesses a [Mn(III)(7)Mn(IV)(μ(3)-O)(4)(μ(4)-O)(2)(μ(3)-OH)(μ(4)-Cl)(μ(2)-Cl)](8+) core consisting of two body-fused Mn(4) butterfly units attached to the remaining Mn atoms via bridging O(2-), OH(-), and Cl(-) ions. In contrast, 2 possesses a [Mn(6)(IV)Mn(2)(III)(μ(3)-O)(6)(μ-O)(3)](12+) core consisting of two [Mn(3)O(4)] incomplete cubanes linked by their O(2-) ions to two Mn(III) atoms. The cores of 1 and 2 are unprecedented in Mn chemistry. The [Mn(III)(9)(μ(3)-O)(7)](13+) core of 3 also contains two body-fused Mn(4) butterfly units, but they are linked to the remaining Mn atoms in a different manner than in 1. Solid-state direct current (dc) and/or alternating current (ac) magnetic susceptibility data established S = (15)/(2), S = 2, and S = 1 ground states for 1·MeCN, 2·(1)/(4)MeCN, and 3, respectively. The ac susceptibility data also revealed nonzero, frequency-dependent out-of-phase (χ″(M)) signals for 1·MeCN at temperatures below 3 K, suggesting possible single-molecule magnet behavior, which was confirmed by single-crystal magnetization vs dc field scans that exhibited hysteresis loops. The combined work thus demonstrates the continuing potential of comproportionation reactions for isolating high oxidation state Mn(x) clusters, and the sensitivity of the product identity to minor changes in the reaction conditions.

It is not known whether obesity has a differential effect on allogeneic haematopoietic cell transplantation outcomes with alternative donor types. We report the results of a retrospective registry study examining the effect of obesity [body mass index (BMI) > 30] on outcomes with alternative donors (haploidentical related donor with two or more mismatches and receiving post-transplant cyclophosphamide [haplo] and cord blood (CBU)] versus matched unrelated donor (MUD). Adult patients receiving haematopoietic cell transplantation for haematologic malignancy (2013-2017) (N = 16 182) using MUD (n = 11 801), haplo (n = 2894) and CBU (n = 1487) were included. The primary outcome was non-relapse mortality (NRM). The analysis demonstrated a significant, non-linear interaction between pretransplant BMI and the three donor groups for NRM: NRM risk was significantly higher with CBU compared to haplo at BMI 25-30 [hazard ratio (HR) 1.66-1.71, p < 0.05] and MUD transplants at a BMI of 25-45 (HR, 1.61-3.47, p < 0.05). The results demonstrated that NRM and survival outcomes are worse in overweight and obese transplant recipients (BMI ≥ 25) with one alternative donor type over MUD, although obesity does not appear to confer a uniform differential mortality risk with one donor type over the other. BMI may serve as a criterion for selecting a donor among the three (MUD, haplo and CBU) options, if matched sibling donor is not available.