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The short-lived buckling instability is responsible for the formation of at least some box/peanut (B/P) shaped bulges, which are observed in most massive, $z=0$, barred galaxies. Nevertheless, it has also been suggested that B/P bulges form via the slow trapping of stars onto vertically extended resonant orbits. The key difference between these two scenarios is that when the bar buckles, symmetry about the mid-plane is broken for a period of time. We use a suite of simulations (with and without gas) to show that when the buckling is sufficiently strong, a residual mid-plane asymmetry persists for several Gyrs after the end of the buckling phase, and is visible in simulation images. On the other hand, images of B/P bulges formed through resonant trapping and/or weak buckling remain symmetric about the mid-plane. We develop two related diagnostics to identify and quantify mid-plane asymmetry in simulation images of galaxies that are within 3{\deg} of edge-on orientation, allowing us to test whether the presence of a B/P-shaped bulge can be explained by a past buckling event. We apply our diagnostics to two nearly edge-on galaxies with B/P bulges from the ${\it Spitzer}$ Survey of Stellar Structure in Galaxies, finding no mid-plane asymmetry, implying these galaxies formed their bulges either by resonant trapping or by buckling more than $\sim 5$ Gyr ago. We conclude that the formation of B/P bulges through strong buckling may be a rare event in the past $\sim 5$ Gyr., Comment: Accepted for pubblication in MNRAS

Three new amine functionalised tetracarboxylate linkers with a variety of arm lengths were synthesised, namely N,N,N′N′-tetrakis(R1, R2 or R3)-trans-1,4-diaminocyclohexane, R1 = (4-carboxyphenyl)-1-methyl; R2 = (4-cinnamic)-1-methyl; R3 = 1′-carboxy-[4,4′-biphenyl]-1-methyl. The diagonal length of the linkers, from single crystal structural analysis and obtained by measuring between the furthest oxygen atoms, is 19.4, 24.6 and 27.5 A for L1, L2 and L3, respectively. The sp3 hybridization of the amino groups of the cyclohexyldiamine core and the carbon atoms of methylene spacers permits the rotation of the attached groups to occur around these atomic sites, giving the ligands a flexibility that manifests itself in two main dominant conformations: convergent, where carboxyl arm groups connected to the same nitrogen atom are π⋯π stacking, and divergent, where two carboxyl arms occupy equatorial positions and two occupy the axial positions relative to the ligand's cyclohexyl core. Analysis of the overall ligand conformations obtained from crystal structures of sixteen new coordination polymers showed that the overwhelmingly most common conformation (93%) was the divergent one. The formulae and topologies of the coordination polymers obtained were: poly-[Cd2(H2L1)(Cl)2(OH2)2]·5H2O (1) 2D (4,4), poly-[M2L2(OH2)2]·DMA M = Cd (2Cd) or Mn (2Mn) 3D (4·62·7·8)(42·66·75·82), poly-[Cd2(L3)(OH2)4(DMF)2] (3) 1D ladder, poly-[Cd2(L3)]·4DMA·16H2O (4) 3D fsc, poly-{((CH3)2NH2)4[Zn4Na4(L1)4(OH2)4(DMF)2]} (5) 3D pts, poly-[M5(HL1)2(O)2(OH2)2(DMF)2]·solv M/solv = Zn/2DMF·18H2O (6Zn) or Co/9DMF·10H2O (6Co) 3D cyc, poly-[Zn3(L1)(OH)2]·2DMF (7) 3D fsc, poly-{((CH3)2NH2)[Zn2(HL2)(O)]·DMF} (8) 3D pts, poly-[Zn8(L3)3(O)2]·16DMF (9) 3D fsy, poly-[Cu2(L1)(DMF)2] (10) 2D (4,4), poly-[Cu2(L2)(OH2)2] (11) 3D lvt, poly-[Na4Zr2(L1)3(DMF)4] (12) 3D (44·52)2(44·5·6)(46·513·68·7)2, poly-[Zr6(HL1)2(O)8(CH3COO)2(OH2)6] (13) 3D scu, and poly-[Co2K4(L1)2(DMF)3] (14) 3D (42·64)(42·610·83). Although we applied similar reaction conditions, none of the coordination polymers obtained with L1, L2 & L3 were isoreticular upon ligand change. The overall trend is of void space increase by using longer ligands but with no notable increase in the level of interpenetration. The predictability and control of the obtained frameworks was hindered by the formation of non-default topologies due to the high flexibility of the tetracarboxylate linkers used and the variety of metal nodes observed.

The major-axis density profiles of bars are known to be either exponential or 'flat'. We develop an automated non-parametric algorithm to detect flat profiles and apply it to a suite of simulations (with and without gas). We demonstrate that flat profiles are a manifestation of a bar's secular growth, producing a 'shoulder' region (an overdensity above an exponential) in its outskirts. Shoulders are not present when bars form, but develop as the bar grows. If the bar does not grow, shoulders do not form. Shoulders are often accompanied by box/peanut bulges, but develop separately from them and are independent tracers of a bar's growth. They can be observed at a wide range of viewing orientations with only their slope varying significantly with inclination. We present evidence that shoulders are produced by looped x1 orbits. Since the growth rate of the bar moderately correlates with the growth rate of the shoulder strength, these orbits are probably recently trapped. Shoulders therefore are evidence of bar growth. The properties of the shoulders do not, however, establish the age of a bar, because secondary buckling or strong spirals may destroy shoulders, and also because shoulders do not form if the bar does not grow much. In particular, our results show that an exponential profile is not necessarily an indication of a young bar., Comment: 20 pages, 23 figures, 2 tables. Published in MNRAS

Mixed donor phenanthroline-carboxylate linkers were combined with MnII or ZnII to form photoactive MOFs with large pore apertures. The MOFs display high CO2 adsorption capacities, which consequently causes structural framework flexibility, and align with favorable metrics for selective CO2 capture. The photophysical properties of the MOFs were investigated, with the MnII MOF giving rise to short triplet LMCT lifetimes.

We use an $N$-body+smoothed particle hydrodynamics simulation of an isolated barred galaxy to study the age dependence of bulge longitudinal proper motion ($��_l$) rotation curves. We show that close to the minor axis ($|l| \sim 0^\circ$) the relatively young stars rotate more rapidly than the old stars, as found by Hubble Space Telescope in the Milky Way's (MW's) bulge. This behaviour would be expected also if the MW were unbarred. At larger $|l|$ a different behaviour emerges. Because younger stars trace a strong bar, their galactocentric radial motions dominate their $��_l$ at $|l| \sim 6^\circ$, leading to a reversal in the sign of $\left< ��_l \right>$. This results in a rotation curve with forbidden velocities (negative $\left< ��_l \right>$ at positive longitudes, and positive $\left< ��_l \right>$ at negative longitudes). The old stars, instead, trace a much weaker bar and thus their kinematics are more axisymmetric, resulting in no forbidden velocities. We develop metrics of the difference in the $\left< ��_l \right>$ rotation curves of young and old stars, and forbidden velocities. We use these to predict the locations where rotation curve reversals can be observed by HST and the Vera Rubin Telescope. Such measurements would represent support for the amplitude of the bar being a continuous function of age, as predicted by kinematic fractionation, in which the bar strength variations are produced purely by differences in the random motions of stellar populations at bar formation., 20 pages, 18 figures, 2 tables, published in MNRAS