Avance III 400 info

Avance III 400 MHz

This lower-field spectrometer, equipped with a 60 positions carousel and a robotic arm for automatic sample changing, is particularly suitable for routine analysis of low molecular weight compounds.

The spectrometer is equipped with four probe-heads, all of them automatically tunable and with Z-axis pulse-field gradients, capable of performing a broad range of experiments such as 1D or 2D homo- and heteronuclear correlation spectra, with or without broadband decoupling of X nuclei.

Description and history of the equipment:

The spectrometer was acquired by the Rede Nacional de RMN (National NMR Network) in November 2006, and its installation completed in December of the same year. The equipment, controlled via Topspin 3.2 software installed in a PC with the LINUX operating system, comprises a micro-bay AVANCE II+ console and a 400 MHz Ultra-Shield-Plus Magnet with 54 mm diameter standard bore and an automatic sample changer. The 5 Gauss magnetic field safety line is described by an ellipsoid with a horizontal and vertical radius of 0.5 m and 1.0 m from magnetic center, respectively.

Two systems are available for low temperature operation:

1. BCU-05 - a nitrogen gas cooling system (exit gas temperature of -20ºC) allowing working temperatures down to 0ºC (approximately);
2. A nitrogen gas cooling system operating by heat exchange with liquid nitrogen allowing working temperatures down to -120ºC (approximately).

Table of sensitivities (signal to noise ratios) for probe-heads:

BBFO-z X-H

The BBFO-z X-H-D (5 mm) is a broad-band probe-head build-up for direct observation of ¹⁹F or any other nuclei within the frequency range from ³¹P to ¹⁰⁹Ag, proton decoupling and pulse-field gradients along Z axis are applicable and it is automatically tunable.

This probe-head is, mostly, used for routine work. Being optimized for X nuclei direct observation, it can lead, as well, to excellent results when studying compounds containing low natural abundance nuclei such as ¹¹B, ¹³C, ²⁹Si, ⁵⁹Co, ⁹⁷Mo, ^119/117Sn, ^111/113Cd, ¹⁹⁵Pt etc.

BBI(F)-z H-X

The BBI(F)-z H-X-D (5 mm) is a probe-head with inverse detection (optimized for ¹H observing), wide range frequency decoupling possibility (from ³¹P to ⁹⁷Mo), with pulse-field gradients along Z axis and automatically tunable. This probe-head is suitable for small molecules structural studies based on homonuclear (e.g., COSY, NOESY, TOCSY, etc.) or heteronuclear (e.g., HSQC, HMQC, HMBC, etc.) correlations and their multiple combinations (HSQC-TOCSY, HSQC-NOESY, etc.).

Proton-NMR experiments requiring heteronuclear decoupling, solvent suppression, dynamic NMR studies and DOSY technique can, also, be performed. Changing the routing of the ¹H channel, ¹⁹F can be directly observed.

BBO-z X-H

The BBO-z X-H-D (10 mm) is a wide frequency range direct observing (from ³¹P to ¹⁰⁹Ag) and ¹H decoupling probe-head, equipped with pulse-field gradients along Z axis and automatically tunable. This accessory is, mostly, used for routine work.

Due to the optimization for X nuclei direct observation, it can lead, as well, to excellent results when studying compounds containing low natural abundance nuclei such as ¹³C, ²⁹Si, ⁷⁷Se, ^119/117Sn, ^111/113Cd, ¹⁸⁵Re, etc.

Being a 10 mm probe-head, it can also be used for in vivo NMR studies.

Minimum sample volume: 2.5 ml
Working temperature range: +150 a -130ºC
Purchase date: 2007

BBO-z X-H LR

The BBO-z LR X-H-D (10 mm) is a probe-head equipped with pulse-field gradients along Z axis and automatically tunable. Especially build-up for direct observation of low frequency nuclei (from ³⁹K to ⁴¹K), it is suitable for inorganic and coordination chemistry NMR studies involving low frequency nuclei such as ⁵⁷Fe, ⁹⁹Ru, ¹⁰³Rh and ¹⁸³W.

Minimum sample volume: 2.5 ml
Working temperature range: +150 a -130ºC
Purchase date: 2007