Spectral sensitizing dyes

PE ,

Here are the 5 dyes from your list from first to fifth.
Are they enough to solve rgb sensitization or do I need to continue ?

Umut

Mustafa Umut Sarac said:

PE , What is the molecular formula of 6,6 diethoxy 1,1 diethyl 2,4 dimethyl 2,4 carbocyanine iodide ?

Umut

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Umut;

It would take me a while to work out the structure, and I doubt if it would do anyone any good.

As for providing R/G/B sensitivity, we do have dyes already posted here that do the trick and so I have no concern about it being a problem. Except for the cost, these dyes are available.

Now, as to their working, some dyes work and some do not on any given emulson. I have 5 or 6 dyes that I tried and got 2 that work on all emulsions, but one is weak and the other sensitizes at a long green wavelength. Another one only works well on bromide emulsions as a green but works on bromo / iodide emulsions as either a red or green. This dye has been the subject of much discussion here.

So, I cannot answer your question about "solving the problem" until I did an experiment with at least 3 emulsions with each dye. You can see how time consuming and expensive that will be. I've already done the ones about, 6 or 7 dyes with 3 emulsions and have published the good results either here or in the book.

PE

Mustafa Umut Sarac said:

View attachment 52697CB4433150
Chemical Name: CRYPTOCYANINE
Molecular Formula: C25H25IN2
Formula Weight: 480.38
CAS No.: 4727-50-8 ....

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Ok, here we go, a proof of concept... $52/gram, minimum order of $100.

http://chemicals.citychemical.com/i...ver=10&categid=100&prodid=1053&origin=keyword

Now, of course there's a lot more to consider here, like Ron says, but with a little effort and creativity I think we can find sensitizers that won't break the bank, hopefully one that does a good job with red.

Umut, awesome job. However, is it necessary to copy and paste all of that?!

PE, Chris and all ,

I attached links to check prices in China and compare with others. Chris , orepare a email template send it to Chinese companies with list attached. They will never lost your e mail address and you will recieve every week a mail starting with Hello Freind not Friend in next 3 years whick makes you want to raze his triangle beard under his jaw , chin )

I got some cryptocyanine from Sigma-Aldrich 1½ years ago, the price was 43 EUR (about 55 USD) for 250 mg. As you might guess, I haven't got time to test it.

So, that one looks quite a bit more attractive, given the much lower price and the fact that buying from Sigma-Aldrich may not be very straightforward (at least you need a company).

And presumably it's a red sensitizer, right? Are all cyanines gonna be on the red end of things? I guess that would make sense... hence cyan!

I think it'd be really great to get a big list of sensitizers, complete with references outlining where it's mentioned, by whom, when, etc. Then as we learn things about them we can fill in the rest of the information.

Unless I'm just missing something really obvious, I don't think a comprehensive sensitizer survey exists. Something to strive for at least.

Do not automaticaly exclude all green sensitizing dyes from the red sensitizing list. When I started working with green sensitive SDE3008, I got very frustrated when my "green sensitized" emulsions, with only SDE3008 kept turning bright violet. I, in fact, had a panchro emulsion and did not know it. It did not seam funny at the time. But I was shure I had not made an adition mistake. Yet the evidence said I had. Or so I thought.
As it is turning out, I do not need a second dye, SDA3057, for red sensitzation.
Bill

holmburgers said:

I think it'd be really great to get a big list of sensitizers,

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Perhaps these dyes (www.few.de/English/index.htm) will be part of that list as well.

Excellent list of dyes at Few Chemicals. Kodak is using water soluble dyes in some of their current products.

PE

holmburgers said:

Ok, update to an old(ish) thread.

This dye, Erythrosine B (CAS: 54530) or Acid Red 51, is available here on eBay for chump change. This dye is in the Kodak list above.

I'm really interested in finding cheap sensitizing dyes for spectral sensitizing, and not necessarily because I am going to try to make a color-sensitive film tomorrow, but to put the possibilities forth so that anyone making emulsions might be inclined to experiment with this stuff down the road.

Sure they might not be the best or most efficient, but they will work, no?

Also, to make panchromatic dichromated gelatin for holograms they use methylene blue as a red sensitizer and Rhodamine G6 for blue/green. Do these dyes have any effect on silver-halides?

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Hi All,

I'm bumping Chris's comment to the front of the line with an example of how effective the older (cheaper and available) sensitizers can be. I'm using erythrosin in my current favorite emulsion. The ASA (old term for old emulsion ) is hitting around 125 at high summer, sea level, on the 45th. Higher in the mountains. The red food dye is what makes this possible. Right now, I have the first of my attempts with pinacyanol chloride and pinaflavol drying in the darkroom. It would take the wildest of luck to make the first experiment successful, but I'm sure it will get there --- because it got there before. That's the beauty of this. Pan (or even near-pan) emulsions open up a world of possibilities, most notably color -- my Holy Grail. But, also hopefully, these kinds of film speeds even in the winter.

Anyway, all this was mostly an excuse to share a video from my part of planet. http://video.msnbc.msn.com/rock-center/48007076/#48007076 and my take on the event: http://www.thelightfarm.com/cgi-bin/htmlgen.py?content=27Jun2012.

Best of weekends with lots of photography -- whatever your camera.
d

Hi Denise,

I'm very interested to know how it's going with your pan sensitizing. According to your most recent post on TLF it sounds like things are going very well (??). Your ortho emulsions are looking really great too!

Yeah, even near-pan is something exciting. Afterall, Autochromes weren't really sensitive to deep red if I understand correctly; mostly orange.

Bi-packs, tri-packs, screen-plates; I think things are moving in this direction... and it's very exciting.

Hi All,
Just to let you all know that I ain't dead, I will write of my current status with regard to emulsions.
I have decided to suspend my own work on finding a panchromatic (set) of sensitizing dye(s). Due to my growing impatience to get back to making art, I will settle for my existing system which uses Sands SDE3008 as my sole sensitizing dye. At least in my system this dye sensytizes evenly across the visible spectrum in open daylight. At least as I can judge from a Kodak Color Card and actual photographs. This Dye is ridiculusly expensive. So I will be watching this forum and Denise's TLF for "pointers". But I fear that I am geting, temperarily I hope, burned out with research.
I am now making my own AgNO3 to save in costs. A little risky, but worthwhile from a cost standpoint.
My first atemps at "real art" using my emulsion will be with tri-color Carbon Transfer, using my existing emulsion to make in-camera color seps. Then I intend to use the emulsion itself , pigmented, in place of gelatin in the actual Carbon Print.
For now,though, I will just be a "lurker" on this forum.
Cheers,
Bill

A referece work

IDK if this has been posted before, but download a copy of this excellent reference, "Photography, It's Materials and Processes" and read the chapter entitled "Color Sensitizing of Photographic Emulsions." Very good explanation.

http://archive.org/details/photographyitsma001646mbp

According to archive.org this book is out of copyright and is publicly available. Haven't read the rest of the book yet, but I imagine it is just as good.

Your link seems to be bad.

Sorry, the link is fixed now. Jason

Like most books on emulsions, it speaks in generalities for the most part.

PE

Just found this website. http://www.spectrum.kiev.ua/catalogue/?class=DY Spectrum Info - Fine Chemicals in Kiev, Ukraine.

Spectrum Info Ltd. is a private company focused on laboratory scale synthesis of fine organic chemicals and combinatorial building blocks. We provide rare and commercially unavailable compounds for research chemists worldwide. Our office and laboratory facilities are located in the Institute of Organic Chemistry, National Academy of Sciences of Ukraine, Kiev.

About 500 synthetic dyes of various classes covering the absorbance range 350-1100 nm are presented in the product list. Specialty dyes catalog includes laser dyes, fluorescent probes, dyes for WORM disks production and electrophotography, silver halide sensitizers for visible and near IR region, and indicators.

Seems promising. I haven't identified any sensitizers yet, but searching "cyanine" brings up 26 hits.

Here's a good thread over at holoforum.org about sensitizing dyes... http://holoforum.org/forum/viewtopic.php?f=9&t=494

Some of the links to various dye companies seem like good bets for obtaining these dyes.

http://www51.honeywell.com/sm/speci...s-n2/functional-dyes-n3/sensitizers.html?c=23
http://www.corchim.ru/catalog/Phot-sen_PH.html (google translated, here)
http://www.organica.de/en/download/12940-Specification.pdf (it's interesting; this dye is sold at HW Sands, but as a functional laser dye, not necessarily advertised as a red sensitizer as it is at this website.)

Review of Literature for Sensitizing Dyes

Ok, this is a work in progress, but this is the result of some armchair research I've done through, primarily, Google Books. It's a smattering of information relating to sensitizing dyes, and particularly those pre-1930ish.

Please download the word file for links, some quotations and a better sense of the context.

I don't claim to be making any conclusions here, but am rather just trying to get a base of information together. I recommend that people go through the links themselves and lets start discussions on certain topics. On the other hand, I don't know if we can conclude too much without some actual testing, but all this literature will certainly point us in the right direction and give us things to consider. In particular, some of the large reference lists should be very valuable for anyone wanting to go deep.

A lot of the literature is relating to bath sensitizing, much of which is done for astrophotography. There appear to be several contradicting statements in the various sources, so be careful in jumping to conclusions. Lastly, I've undoubtedly missed sources and indeed, haven't claimed to do an exhaustive search. I would simply search "pinacyanol", "orthochrome", or other dye names in Google books and follow the links which looked promising.

Here is a fairly complete list of all the sensitizers that are mentioned, posted mainly for the purpose of keyword searches. It'd be best to read the literature for broader context and use of the dyes . . . . .

Earliest Survey after Vogel:
- Ethyl Violet (triphenylmethane dye) - "red sensitizer for collodion"
- Eosin, Erythrosin, Rose Bengal (pyronine dyes) - "green and yellow sensitizers"
- Fast Red, Congo Red, Glycine Red, BenzoNitrol Brown (azo dyes)
- Acridine Orange, Alizarin Blue

Cyanine, a.k.a. quinoline blue
- 1,1'-Di-n-amyl-4,4'-cyanine iodide

In 1903, Miethe & Traube patented Ethyl Red (an isocyanine).
- 1,1'-Diethyl-2,4'-cyanine iodide
- sensitizer for green, yellow and orange
- a.k.a. chinaldin-ethyl-cyanin

In 1905, Homolka at Hoechst Dye Works discovered Pinacyanol.
- 1,1'-Diethyl-2,2'-carbocyanine iodide (or bromide, or chloride)
- Structure wasn't elucidated until mid-20's through research by Pope.

Dicyanine and Dicyanine A were manufactured later by Hoechst.
- 1,1'-Diethyl-2,4'-carbocyanine iodide (dicyanine)
- 6,6'-Diethoxy-1,1'-diethyl-2,4-carbocyanine iodide (dicyanine A)

Woolblack – a red sensitizer for gelatin
Pinaverdol - a green sensitizer

Orthochrom T
Pinachrom (pinachrom violet (?))
Homocol
Pinaflavol

Kryptocyanine (1919), Neocyanine (1925), Xenocyanine & other tricarbocyanines (1931) - IR sensitizers

In summation, “Pinacyanol, the most important sensitizer for the red, was used in all panchromatic materials until the thirties. Although by itself it gives fairly good sensitivity in the green in addition to its major contribution in the red, it was usually employed in conjunction with other dyes such as Orthochrome T, Pinaverdol, or pinachrome which conferred greater response in the green.”

Autochrome screen dyes are panchromatic sensitizer dyes also

Hello Chris ,

Are you aware of many early red, green and you call azo emulsion sensitizer dyes are used in original autochrome screen starch dyeing recipe. Its would not be a suprise to find them in autochrome panchromatic RRGGBB screen backing emulsion.

Very important finding I think.

Thank you for hard work , try to contact with Ukraine and obtain their price catalog. They are very Soviet times prices.

Umut

Thanks Umut for the kind words. I didn't notice that about the autochrome screen, that's very interesting indeed.

I agree that Ukraine prices are probably very desirable.

Ciao!

By the way , If I am not wrong there are more than 900 universities at Ukraine and they do one of the most hardcore researches in the world.

At Kiev , one school teacher gets 100 dollars a month .

I contacted with a Inflatable Boat seller , giant boat comes for 60 dollars including shipment. They are living hard times.

Another story , someone advertised Hologram Business Cards at some forum , I asked the price , 50 business card costs more than 500 dollars due to preparing the films.

I contacted with Kiev university Enterprize and 1000 hologram business card costs 100 dollars.

What else ?

Umut

How relevant are sensitizing dyes used for solar cells? A lot of research is going on. For example:

Here we report on the sensitization of semi-
conductor particles (TiO2 ) by organic dyes such
as xanthenes (rhodamine 101, fluorescein and 5(6)-
carboxyfluorescein) and azo dyes (alizarin yellow R,
alizarin yellow 2G and carboxyarsenazo). Photostabil-
ity of these dyes will be determined for possible use
as sensitizers for the nanocrystalline solar cell. The
role played by redox couple (e.g. I3 − /I− ) electrolyte
in regenerating the neutral sensitizer dye molecules,
and thus, stabilization of the dye molecule will be also
studied. The chosen dyes possessing carboxylate or
hydroxyl function groups that enable direct interaction
with the surface of TiO2 particles, thereby providing
a path for electron transfer from the excited dye
adsorbate to the semiconductor.....

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From "The interaction and photostability of some xanthenes and selected azo sensitizing dyes with TiO2 nanoparticles", D. EL Mekkawi and M. S. A. Abdel-Mottaleb

Also, US Patents 4173478 and 4476220 discuss azo dyes as silver halide photographic sensitizers. They do discuss heat processed materials, though.

kb3lms ,

I opened a thread last year on tio2 use , it has ultrawide spectrum and even with coating with dyes increases the end power of solar cell. I dont think a printed on film solar cell maker wants to invent and use a expensive dye , so the widest available dye would be the selection with some drawbacks.

My intention is to use titanium dioxide in the place of silver. If I remember correctly , a reducing agent was needed and final decision was it would cost more than buying silver. Its silly but without forum support , I dont lots of options.

You can dig it now and if you can.

By the way , I saw rhodamine , it doesnt work if you dont freeze it. Alizarin dyes are cheap and widely available and I am right , they want to make the lowest cost device.

Umut

(there was a url link here which no longer exists)