The Vibration Spectra of Hydrazoic Acid, Methyl Azide, and Methyl Isocyanate The Thermodynamic Functions of Hydrazoic Acid

The vibration spectra of hydrazoic acid, methyl azide, and methyl isocyanate have been investigated in the spectral region between 2 and 20μ. Correlation of the spectra of these structurally similar molecules has made possible the determination of all the fundamental frequencies of hydrazoic acid and all but the methyl torsion frequency in the methyl compounds. From these fundamental frequencies and the known rotational constants, the usual thermodynamic functions of hydrazoic acid have been calculated to the harmonic oscillator‐rigid rotator approximation. Equilibrium constants for some characteristic reactions have also been obtained.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70737/2/JCPSA6-8-5-369-1.pd

Die Schwingungsspektren von Natrium- und Zinkhydrazid

Nach bekannten Verfahren wurden Natrium- und Zinkhydrazid dargestellt. Das Zinksalz hat im Gegensatz zu den bisherigen Angaben die Zusammensetzung Zn(N2H3)2. Von beiden Verbindungen wurden die IR-Spektren aufgenommen und die Bindungsverhältnisse diskutiert. Beim Natriumsalz zeigt sich die erwartete Lockerung der N-N-Bindung gegenüber Hydrazin. Im Zinkhydrazid wird aus der Verfestigung der N-N-Bindung gegenüber Hydrazin auf Komplexbildung mit kovalenter Bindung Zn-N geschlossen.Sodium and zinc hydrazide were prepared by known procedures. For the zinc salt, the composition Zn(N2H3)2 was found, contrary to previous claims. IR-spectra of both substances were taken and discussed with regard to bond properties. The sodium salt shows the expected weakening of the N-N-bond compared to N2H4. In the zinc salt, having stronger N-N-bonds than N2H4, covalent Zn-N-bonds are assumed

Darstellung, Kristallstruktur und IR-spektroskopische Untersuchung von Phosphor(V)-nitrid-imid, HPN2

Reines und feinkristallines Phosphor(V)-nitrid-imid (HPN2) wurde durch heterogene Ammonolyse von P3N5 mit gasförmigem NH3 (T = 580°C, p = 30 bar, 6d) dargestellt. Die Kristallstruktur von HPN2 wurde auf der Basis von Röntgen-Pulverdiffraktometerdaten mit Hilfe der Rietveld-Methode verfeinert (I2d, a = 461,82(2) pm, c = 702,04(3) pm; Z = 4; 41 beobachtete Reflexe, 17° < 2 < 125°; CuK1, Germanium-Monochromator; R(wp) = 0,072; R(I,hkl) = 0,048). Im Festkörper ist HPN2 aus einem dreidimensionalen Netz allseitig eckenverknüpfter PN4-Tetraeder (PN: 159,9(4) pm; PNP: 130,1(4)°) aufgebaut. Die H-Atome sind kovalent an die Hälfte der N-Atome gebunden. Im IR-Spektrum werden sechs Schwingungsbanden (v(NH): 3224; vas(PNP): 1330, 1223; vas(PNHP): 971, 901; (PNP): 531 cm-1) beobachtet

Prognosis of hyperviscosity syndrome in newly diagnosed multiple myeloma in modern-era therapy: A real-life study

Hyperviscosity syndrome (HVS) is a rare complication of newly diagnosed multiple myeloma (NDMM) related to high tumour burden. Studies about the prognosis of HVS in modern-era therapy for NDMM are missing. We investigated a retrospective cohort study of NDMM with HVS between 2011-2021. Thirty-nine NDMM patients with HVS were included. HVS presentation was heterogeneous, with asymptomatic, mild, and neurological forms in 23%, 59%, and 18% of cases, respectively. No thrombosis or major bleeding was observed. Therapeutic plasma exchanges were used in 92% of patients, which were effective and well tolerated. No rebound effect was observed. All patients except one had at least one CRAB criterion. Most of the patients received bortezomib and high-dose steroids (95%) associated with an immunomodulatory drug (43%) or alkylating agents (42%). HVS in NDMM patients had dismal overall survival matched to multiple myeloma patient controls (without HVS) in our center (median: 3.6 vs. 7.7 years, p=0.01), as confirmed by multivariate analysis. Early deaths (in the first two months) occurred in 21% of older patients (&gt;65 years). HVS in NDMM patients is a rare but life-threatening complication associated with high lethality in older patients and be a potential dismal prognosis factor in the modern treatment era

Reductive N–N coupling of NO molecules on transition metal complexes leading to N2O

Nitric oxide reductase (NOR) type reactions (2NO + 2e- + 2H+ → N2O + H2O) on transition metal complexes not involving NO disproportionation (3NO → N2O + NO2) are reviewed. The former has little reported, although the latter is very common reaction. The formation of N2O indicates that N-N coupling of two NO molecules is an essential step. A few examples of N-N coupling on transition metal complexes have been structurally characterized, including several examples of hyponitrite (O-N{double bond, long}N-O)2- complexes and only one diruthenium complex bearing neutral (O{double bond, long}N-N{double bond, long}O) binding mode. Protonation or heating their complexes led to elimination of N2O. In the examination of the NOR-type reaction, only a few functional model complexes for the active site of the metalloenzyme have been developed. These complexes also showed NOR activity. Finally, an NO reduction cycle in the diruthenium system is described

Understanding the Role of Hyponitrite in Nitric Oxide Reduction

Herein, we review the preparation and coordination chemistry of cis and trans isomers of hyponitrite, [N2O2](2-). Hyponitrite is known to bind to metals via a variety of bonding modes. In fact, at least eight different bonding modes have been observed, which is remarkable for such a simple ligand. More importantly, it is apparent that the cis isomer of hyponitrite is more reactive than the trans isomer because the barrier of N2O elimination from cis-hyponitrite is lower than that of trans-hyponitrite. This observation may have important mechanistic implications for both heterogeneous NOx reduction catalysts and NO reductase. However, our understanding of the hyponitrite ligand has been limited by the lack of a general route to this fragment, and most instances of its formation have been serendipitous