A participação de PMEs portuguesas em alianças de I&D: programa CRAFT

A formação de alianças de base tecnológica conheceu um incremento notável nas décadas de 1980 e 1990, representando actualmente uma estratégia empresarial importante de acesso ao conhecimento tecnológico, fortemente incentivada pela generalidade dos países da OCDE. A literatura sobre alianças realça as enormes vantagens mútuas que podem resultar da cooperação tecnológica bem sucedida. Raramente, porém, são abordados empiricamente os problemas específicos da participação de PMEs em alianças de I&D, e menos ainda quando essas empresas pertencem a sectores tradicionais e têm limitações evidentes para participar em alianças de I&D. Este trabalho aborda esta problemática no quadro da participação de PMEs portuguesas no programa europeu CRAFT (1994-98). Os resultados indicam que o empenhamento dos parceiros, os aspectos culturais e a falta de recursos internos representam os aspectos mais negativos da cooperação. Isto é, em grande medida, consequência das condições iniciais que estiveram na génese das alianças mas a estrutura das alianças também é importante. As PMEs portuguesas ficaram, em geral, satisfeitas com os benefícios obtidos mas o sucesso técnico da aliança não garante que as empresas tenham condições para materializar os benefícios potenciais gerados no âmbito da aliança

‘Aggregation-Induced Emission’ Active Mono-Cyclometalated Iridium(III) Complex Mediated Efficient Vapor-Phase Detection of Dichloromethane

Selective vapor-phase detection of dichloromethane (DCM) is a challenge, it being a well-known hazardous volatile organic solvent in trace amounts. With this in mind, we have developed an ‘Aggregation-induced Emission’ (AIE) active mono-cyclometalated iridium(III)-based (M1) probe molecule, which detects DCM sensitively and selectively in vapor phase with a response time <30 s. It reveals a turn-on emission (non-emissive to intense yellow) on exposing DCM vapor directly to the solid M1. The recorded detection limit is 4.9 ppm for DCM vapor with pristine M1. The mechanism of DCM detection was explored. Moreover, the detection of DCM vapor by M1 was extended with a low-cost filter paper as the substrate. The DCM is weakly bound with the probe and can be removed with a mild treatment, so, notably, the probe can be reused

Strategic design and synthesis of AIEE (Aggregation Induced Enhanced Emission) active push-pull type pyrene derivatives for the ultrasensitive detection of explosives

Tuning of solid and solution phase emission with simple push-pull ‘Aggregation Induced Enhanced Emission’ (AIEE) pyrene compounds for deeper understanding on the mechanism for selectivity and sensitivity towards the nitro explosives with lowering the detection limit upto ppt (parts per trillion) level. Keywords: AIEE 1, Ultrasensitive explosive detection 2, Photo induced electron transfer and energy mechanism

Construction of a unique three-dimensional array with cadmium (II)

The complex [Cd₃(dien)₂(NCS)₆]_n•nH₂O (dien = diethylenetriamine) is prepared and characterised by X-ray diffraction studies, which show a new type of three-dimensional polymeric structure having cadmium centres which are linked to each other via NCS bridges in such a way that two types of Cd environment (one involving only N-donor atoms and the other only S-donor atoms) are produced

Achieving Single-Component Solid-State White-Light Emission through Polymerization-Induced Phosphorescent Emission

The non-luminescent monomeric unit M1 transforms into intensely yellow emissive phosphorescent polymers upon polymerization, termed polymerization-induced phosphorescent emission (PIPE). A simple free radical polymerization method is employed for the polymer synthesis where the homopolymer (HP) exhibiting PIPE is generated from vinyl monomers (M1) via non-conjugated bond formation. High photo efficiency observed for the PIPE-active HP may have resulted from the possible intrachain and interchain interactions, among the repeating units. By using various monomer compositions, this synthetic technique provides copolymer and emission tuning. Integrating blue-emitting carbazole with the PIPE-active HP resulted in the white-light-emitting copolymer (CP4). This is the first report on PIPE-active-mediated white-light-emitting copolymer with CIE coordinates (0.25, 0.33). The resulting copolymer (CP4) showed a high quantum yield (33.7%) with a long excited-state lifetime (6.54 μs). PIPE-active phosphorescent-based white-light-emissive polymeric materials could motivate the development of advanced materials for white-light-emitting diode devices

Synthesis and characterization of cis and trans isomers of [NiL₂(NCS)₂] [L=1-(2-aminoethyl)pyrrolidine]: X-ray single-crystal structures

The isomeric complexes trans-[NiL₂(NCS)₂] (violet) (1) and cis-[NiL₂(NCS) ₂] (blue) (2) [L=1-(2-aminoethyl)pyrrolidine] have been synthesized, varying solvents and temperature, and their X-ray crystal structures have been determined. Both the isomers possess the same space group, P2₁/c, having distorted octahedral geometry

Cis–trans isomerism in nickel(II)–diamine nitrite: synthesis and single crystal structure of an unusual cis-dinitronickel(II) complex, [NiL₂(NO₂)₂] (L =1,2-diamino-2-methylpropane)

The complexes [NiL₃](NO₂)₂•2H₂O (violet, 1) and cis-[NiL₂ (NO₂)₂]•0.5H₂O (pink, 1b) (L=1,2-diamino-2-methylpropane) have been synthesized from solution. The X-ray single crystal structure analysis of compound 1b has been carried out, but the presence of a water molecule cannot be detected. Upon heating, complex 1b undergoes dehydration followed by an endothermic phase transition to produce trans-[NiL₂ (NO₂)₂] (1d). The violet species (1) also undergoes dehydration upon heating with deamination resulting (1d)

Flexibility in co-ordinative behaviour of N-(3-hydroxypropyl)-ethane-1,2-diamine toward cadmium(II) halides:syntheses, crystal structures and solid state thermal studies

One new two-dimensional and two one-dimensional organic/inorganic composite coordination polymers have been synthesised by the reaction of cadmium(II) halides with N-(3-hydroxypropyl)ethane-1,2-diamine (L) and structurally characterised. [Cd(L)Cl2]n (1) is a two-dimensional sheet which is built from intersecting zigzag chains and forms a honeycomb like (6,3) net where each octahedral cadmium is linked with two bridging chloride atoms, one pendant chloride atom, two chelated nitrogen atoms of L and an oxygen atom from a neighbouring ligand; each cadmium(II) acts as a branching centre. [Cd(L)Br2]n (2) is a bromo bridged one-dimensional chain in which the non-chelated part of ligand L binds a neighbouring cadmium(II) centre resulting in an alternating array of four- and twelve-membered rings. [Cd(L)I2]n (3) is an iodo bridged one-dimensional network of alternating octahedral (CdN4I2) and tetrahedral cadmium(II) (CdI4) centres. Upon heating the complexes exhibit an irreversible endothermic phase transition [95–133 °C, ΔH = 29.5 kJ mol-1 for (1); 83–128 °C, ΔH = 22.5 kJ mol-1 for (2) and 91–128 °C, ΔH = 15.5 kJ mol-1 for (3)] yielding transparent films of CdLCl2 (1a), CdLBr2 (1b) and CdLI2 (1c) respectively. The derived species (1a, 1b and 1c) do not revert on keeping them in a humid atmosphere (relative humidity ≈ 60%) for several days but exhibit a glass transition upon heating