Development of Land Analysis System display modules

The Land Analysis System (LAS) display modules were developed to allow a user to interactively display, manipulate, and store image and image related data. To help accomplish this task, these modules utilize the Transportable Applications Executive and the Display Management System software to interact with the user and the display device. The basic characteristics of a display are outlined and some of the major modifications and additions made to the display management software are discussed. Finally, all available LAS display modules are listed along with a short description of each

Synthesis and thermoelectric properties of 2- and 2,8-substituted tetrathiotetracenes

Reaction of elemental sulfur with 2-R1 and 2,8-R1,R2-substituted tetracenes (2) in refluxing DMF affords 5,6,11,12 tetrathiotetracenes (1) in good yields (74-99%) for a range of substituents where R1,R2 are: H,H (a); Me,H (b); MeO,H (c); Ph,H (d); Me,Me (e), iPr,Me (f, iPr = iso-propyl, CHMe2), Me,MeO (g); MeO,MeO (h). The reaction rate is limited only by the solubility of the tetracene (2); 2g-h being both the least soluble and slowest reacting. At partial conversion recovered single crystalline 2g led to its X-ray structure determination. Vacuum deposited (substrate deposition temperature 300 K, pressure 7 × 10-6 mbar, source temperature 500 K) thin films from 1 (of initial 88-99% purity) show final electrical conductivities, σ(in plane) from 1.40 × 10-5 S cm-1 (1g) to 3.74 × 10-4 S cm-1 (1b) for the resultant near pristine films; while 1d proved too involatile to be effectively sublimed under these conditions. In comparison, initially 95% pure TTT (1a) based films show σ(in plane) = 4.33 × 10-5 S cm-1. The purities of 1a-h are highly upgraded during sublimation. Well defined micro-crystallites showing blade, needle or mossy like habits are observed in the films. The Seebeck coefficients (Sb) of the prepared 1 range from 374 (1c) to 900 (1f) μV K-1 (vs. 855 μV K-1 for identically prepared 95% pure TTT, 1a). Doping of films of 1f (R1 = iPr, R2 = Me) with iodine produces optimal p-type behaviour: σ(in-plane) = 7.00 × 10-2 S cm-1, Sb = 175 μV K-1. The latter’s Power Factor (PF) at 0.33 μW m-1 K-2 is more than 500-times that of the equivalent I2-doped TTT films (1a, R1 = R2 = H), previously regarded as the optimal material for thin film thermoelectric devices using acene radical cation motifs

Straightforward synthesis of 2- and 2,8-substituted tetracenes

A simple regiospecific route to otherwise problematic substituted tetracenes is described. The diverse cores (E)- 1,2-Ar1CH2(HOCH2)C=C(CH2OH)I (Ar1 = Ph, 4-MePh, 4-MeOPh, 4-FPh) and (E)-1,2-I(HOCH2)C=C(CH2OH)I, accessed from ultra-low cost HOCH2C?CCH2OH at multi-gram scales, allow the synthesis of diol libraries (E)-1,2- Ar1CH2(HOCH2)C=C(CH2OH)CH2Ar2 (Ar2 = Ph, 4-MePh, 4-iPrPh, 4-MeOPh, 4-FPh, 4-BrPh, 4-biphenyl, 4-styryl; 14 examples) by efficient Negishi coupling. Copper-catalysed aerobic oxidation cleanly provides dialdehydes (E)-1,2- Ar1CH2(CHO)C=C(CHO)CH2Ar2 which in many cases undergo titanium(IV) chloride induced double Bradsher closure providing a convenient method for the synthesis of regiochemically and analytically pure tetracenes (12 examples). The sequence is typically chromatography-free, scalable, efficient and technically simple to carry out