Picosecond time-resolved X-ray ferromagnetic resonance measurements at Shanghai synchrotron radiation facility

Abstract

An experimental picosecond time-resolved X-ray ferromagnetic resonance (TR-XFMR) apparatus with a time resolution of 13 ps (RMS) or 31 ps (FWHM) was constructed and demonstrated in the 07U and 08U1A soft X-ray beamlines at the Shanghai Synchrotron Radiation Facility (SSRF) using pump-probe detection and X-ray magnetic circular dichroism (XMCD) spectroscopy. Element and time-resolved ferromagnetic resonance was excited by continuous microwave phase-locking of the bunch clock within the photon beam during synchrotron radiation and was characterized by detecting the magnetic circular dichroism signals of the elements of interest in the magnetic films. Using this equipment, we measured the amplitude of the element-specific moment precession during ferromagnetic resonance (FMR) at 2 GHz in a single Ni81Fe19 layer.

Continuous flow synthesis of the ionizable lipid ALC-0315

“…6,16–18 Since then, several alternative synthetic routes have also been published (Scheme 1). 19–21 The more recent syntheses proceed via an amine alkylation rather than a reductive amination as in the original patents. 22 For example, in the patent by Dong and Tang, 6-bromohexanol (Scheme 1a) was acylated with 2-hexyldecanoic acid 2 using catalytic 4-methylbenzene-1-sulfonic acid (TsOH) to yield 7 in 76% yield, enabling a di-alkylation of 4-aminobutanol to produce ALC-0315 in 87% yield (Scheme 1d).…”

“…22 For example, in the patent by Dong and Tang, 6-bromohexanol (Scheme 1a) was acylated with 2-hexyldecanoic acid 2 using catalytic 4-methylbenzene-1-sulfonic acid (TsOH) to yield 7 in 76% yield, enabling a di-alkylation of 4-aminobutanol to produce ALC-0315 in 87% yield (Scheme 1d). 19,22 Saadati et al recently reported the same synthetic approach, albeit with different conditions for the acylation (86%) and amine di-alkylation (55%) (Scheme 1b and e). 23 Yet another amine-alkylation approach starts with the alkylation of 2-hexyldecanoic acid 2 with 1,6-dibromohexane (Scheme 1c) to yield 7 in 85% yield, with the subsequent amine di-alkylation yielding ALC-0315 in 56% yield (Scheme 1f).…”