ReactIR

ReactIR refers to the real time, in situ monitoring of the IR spectrum of the reaction mixture with a ReactIR 4000 Reaction Analysis System available from AS I Applied Systems. 

To further elucidate the details of the pure NaNT to DBX-1 reaction progress, various reactions to DBX-1 were monitored using in-situ infrared (IR) and Raman spectroscopy. The tools proved valuable in understanding both the intermediate and product formation. The two tools are quite complementary Mettler Toledo s ReactIR (infrared) detects species in solution, while Raman will detect species in both solution and in solid form. 

As described earlier, the ensuing induction period results in an increase in fine particles as monitored by FBRM . The ReactIR also detects an increase in concentration of a species in solution during this induction period (see blue line in Figure 4). The dotted purple line is the Raman intensity of the intermediate over time, whereas the dotted green line is the product DBX-1. The red line is the total dose of sodium ascorbate reducing agent. 

Figure 4. ReactIR trends of intermediate formation and disappearance.

ReactIR 4000 spectrometer (Mettler Toledo, ASI Applied Systems, USA) (optional) chiral-GC /3-Dex 225 column (Supelco Inc.)... 

PCA techniques have been applied to various data sets. From the open literature, I have been unable to find reference to their application to homogeneous catalytic systems. Having said that, it is important to note that the new ReactIR system by Mettler Toledo contains a program ConcIRT. It is a proprie-... 

Figure 8.4 The ASI ReactIR 1000 reaction analysis system with a stainless-steel Parr autoclave modified with permanently mounted ATR crystal (SiComp) at the bottom of the reactor (purchased from Mettler Toledo).

Reaction In situ FTIR Mettler Toledo, ReactIR... 

Figure 2. ReactIR spectra ofthe C-H stretch resonance signal of phenylacetylene in CH3CN. Addition of Et3N and subsequent addition of Zn(OTf)2 resulted in the disappearance of the terminal C-H resonance within 4 min.

Data obtained from similar studies of other compounds are consistent with this simple generalization the reactirity of a hydrogen depends chiefly upon its class, and not upon the alkane to w hich it is attached. Each primary hydrogen of propane, for example, is about as easily abstracted as each primary hydrogen in -butane or isobutane each secondary hydrogen of propane, about as easily as each secondary hydrogen of w-butane or -pentane and so on. 

The presence of the carbonyl group not only lowers the reactirity of the carbon-carbon double bond toward electrophilic addition, but also controls the orientation of the addition. 

Grabarnick, M., Zamir, S. Thorough Examination of a Wittig-Horner Reaction Using Reaction Calorimetry (RC-1), LabMax, and ReactIR. Org. Process Res. Dev. 2003, 7, 237-243. 

Fig. 23. H NMR data (monitoring peaks for bridgehead protons) demonstrating the formation of 47a to 51 and the conversion of 51 to 52 over time. Structural assignments were independently confirmed by ReactIR technology [49]...

Spectral investigations of the catalytic resting states in both asymmetric hydroformylation and hydrocyanation using bisphosphite 1 were performed. Reaction of Rh(CO)2(acac) with 1 equiv of i under 1 1 CO/H2 led to clean formation of Rh(l)(CO)2H. Infrared spectra of the reaction product exhibited bands at 2069, 2015 and 1984 cm. Extensive characterization of this complex by NMR has been published by van Leeuwen.(4) Under 50 psi l.T CO/H2 in the presence of styrene, identical bands were observed by in situ IR using the ReactIR system. 

The ReactIR MP unit is designed from a safety and performance perspective for operations in manufacturing environments. One of the operational problems occasionally encountered with in-line spectroscopic techniques is fouling of optical components. To avoid fouling of the probe and to insure a clean spectroscopic window, the ReactIR MP is equipped with a 200-W ultrasonic... 

FIGURE 22.5 ReactIR (Mettler Toledo) data for formation of dimethyltitanocene. 

Chain polymerisation necessarily involves the three steps of initiation, propagation, and termination, but the reactirity of the free radicals is such that other processes can also occur during polymerisation. The major one is known as chain transfer and occurs when the reactivity of the free radical is transferred to another species which in principle is capable of continuing the chain reaction. This chain transfer reaction thus stops the polymer molecule from growing further without at the same time quenching the radical centre. 

It was not regarded as. a practical necessity that so much reactirity be built unto the reactor that it could override the Xe at all times.after shutdown. However, there should be sufficient extra reactivity so that every accidental scram does not keep the resctbr shut down for several days. It was felt that if the reactor can override X hr of accumulated Xe + Sm , it will ordinarily have sufficient operational flexibility. To achieve this it is necessary, according to Fig 4.3.C, to build into the reactor an excess reactivity of 9.6% (4.7% for reactivity loss in 30 min after shutdown plus 4.9% equilibrium loss). With this available Ak/k the machine can be started up within the first half hour after a scram, or after two days if not started during- the "grace" period. 

---