N_2 Functionalization at Iron Metallaboratranes

The reactivity of the anionic dinitrogen complex [(TPB)Fe(N_2)]^− (TPB = tris[2-(diisopropylphosphino)phenyl]borane) toward silicon electrophiles has been examined. [(TPB)Fe(N_2)]^− reacts with trimethylsilyl chloride to yield the silyldiazenido complex (TPB)Fe(NNSiMe_3), which is reduced by Na/Hg in THF to yield the corresponding sodium-bound anion [(TPB)Fe(NNSiMe_3)]Na(THF). The use of 1,2-bis(chlorodimethylsilyl)ethane in the presence of excess Na/Hg results in the disilylation of the bound N_2 molecule to yield the disilylhydrazido(2−) complex (TPB)Fe≡NR (R = 2,2,5,5-tetramethyl-1-aza-2,5-disilacyclopentyl). One of the phosphine arms of TPB in (TPB)Fe≡NR can be substituted by CO or ^tBuNC to yield crystalline adducts (TPB)(L)Fe≡NR (L = CO, ^tBuNC). The N–N bond in (TPB)(^tBuNC)Fe≡NR is cleaved upon standing at room temperature to yield a phosphoraniminato/disilylamido iron(II) complex. The flexibility of the Fe–B linkage is thought to play a key role in these transformations of Fe-bound dinitrogen

Tetraquark resonances computed with static lattice QCD potentials and scattering theory

We study tetraquark resonances with lattice QCD potentials computed for two static quarks and two dynamical quarks, the Born-Oppenheimer approximation and the emergent wave method of scattering theory. As a proof of concept we focus on systems with isospin $I = 0$, but consider different relative angular momenta $l$ of the heavy $b$ quarks. We compute the phase shifts and search for \mbox{S} and \mbox{T} matrix poles in the second Riemann sheet. We predict a new tetraquark resonance for $l = 1$, decaying into two $B$ mesons, with quantum numbers $I(J^P) = 0(1^-)$, mass $m = 10576_{-4}^{+4} \, \textrm{MeV}$ and decay width $\Gamma = 112_{-103}^{+90} \, \textrm{MeV}$.Comment: 7 pages, 6 figures, 1 table, Proceedings of the 35th International Symposium on Lattice Field Theory, Granada, Spai

Warasdiner Grenze - Extra Entwicklung eine Mikroregion in Drautallgebiet (Podravina)

Nekoliko puta u povijesti austrijskog vojnog kordona u Hrvatskoj Varaždinska je krajina postala polazištem procesa koji su se ubuduće proširili na cjelinu vojnokrajiške ustanove. Riječ je najprije o krajiškoj organizaciji u 17. te o reformama u 18. stoljeću, a potom prije svega o ukidanju Vojne krajine u drugoj polovici 19. stoljeća. U kontekstu likvidacije kordona (osobito u pretpovijesti ovog procesa) specifičan geografski položaj Varaždinske krajine igrao je veliku ulogu. Pogled na statističke podatke iz 19. stoljeća pokazuje da je Varaždinska krajina bila dio ravnomjerno oblikovanog i strukturiranog vojnokrajiškog sustava u Hrvatskoj i Slavoniji.Einige Male in der Geschichte des österreichischen Militärkordons in Kroatien wurde die Warasdiner Grenze zum Ausgangspunkt für Prozesse, die sich in der Folge auf die Gesamtheit der Militärgrenzeinrichtung ausweiteten: Namentlich betrifft dies zunächst die Grenzorganisation im XVII. sowie die Reformen im XVIII. Jahrundert, und dann vor allem die Auflösung der Militärgrenze in der zweiten Hälfte des XIX. Jahrunderts. Im Kontext der Liquidierung des Kordons (besonders in der Vorgeschichte dieses Prozesses) spielte die spezifische geographische Lage des Warasdiner Generalates eine bedeutende Rolle. Ein Blick auf statistische Daten aus dem XIX. Jahrundert zeigt, daß die Warasdiner Grenze Teil eines gleichmäßig ausgeformten und strukturierten Militärgrenzsystems in Kroatien-Slawonien war